


Resonance

by flailinginlove



Category: Naruto
Genre: Icha Icha Series, M/M, chakra resonance, medical ninjutsu handwavium, rating is mostly for the icha icha excerpts
Language: English
Status: Completed
Published: 2019-07-28
Updated: 2019-08-06
Packaged: 2020-07-23 12:42:49
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 21,504
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20008489
Author URL: https://archiveofourown.org/users/flailinginlove/pseuds/flailinginlove
Summary: After being hit by a missing-nin's jutsu, Kakashi's chakra is never the same again.





	1. Chapter 1

**Author's Note:**

> Thank you to Yokoranger for beta reading, and to ladyxxdaydream and pastles for giving me feedback on part of this chapter! ♥
> 
> This is me taking a few lines of throwaway dialog from the anime and one of the movies and expanding upon them to a ridiculous extent. There is also some serious medical ninjutsu handwavium going on here, but I hope it all makes sense (or as much sense as canon at least XD). I will be posting full notes about inspirations and things at the end of chapter 2.

Kakashi ran. Forest flew by him, an indistinguishable green blur as he leapt from tree to tree, covering distance in giant, chakra-burning bounds. He ran with a desperate speed, keenly aware of time slipping away from him. He had to make it back to Konoha, to deliver the intel he'd gathered, if not for himself. His body ached, burned, but not from the strain of his current pace.

It had been a jutsu, one he'd never seen before. He didn't know what it'd done. What it _was doing_. He'd felt it hit, but the effects hadn't been immediate. There had been a faint buzz, a warmth deep in his body, but that was it. It hadn't been enough to distract him from killing the missing-nin, a former medic-nin from Grass Country.

But the death of the missing-nin hadn't stopped the jutsu, if anything it'd gotten worse. It spread and grew. The warmth became a burning in his bones. The buzz, a constant vibration threatening to rattle him apart. 

He ran, ignoring the burning, ignoring the shaking, focused solely on getting home. Each step caused white-hot jolts of pain to lance up his legs and through his body. He ignored that too. There wasn't time for anything else. The speed the jutsu's strength was increasing guaranteed that.

He might not know the finer details of what it was doing, but he didn't need to. It was killing him. 

The tremors became full-body shakes, making his steps unsteady, but he pushed on. Konoha was less than an hour away. He'd make it. What happened after that would no longer be in his control.

He marveled at the clarity of his mind. His head ached, but it wasn't keeping him from thinking. Whatever this was, it wasn't affecting his cognitive functions, instead leaving him with crystal clear awareness of the way his body felt like it was trying to combust, like it was ripping itself to pieces.

He made it past the gates, through the town, into Tsunade's office. He handed over the intel. Then he collapsed.

His last memory was of Tsunade cursing him out as pain overwhelmed him and darkness claimed him.

~*~*~

The white walls and sterile scents of the hospital were never pleasant to wake up to, but at least they meant he wasn't dead. Kakashi tried to push himself into a sitting position only to realize it wasn't going to happen. He felt weaker than a two-day-old ninken. He resigned himself to looking around the room instead. Even turning his head was difficult. His neck was stiff, like he hadn't moved in days.

This wasn't a standard hospital room, that much was immediately clear. It was a single occupancy room, reserved for only the worst cases, and while the window was large, it was the kind that didn't open. Short of breaking it, there'd be no escaping that way. A set of _Icha Icha_ books were sitting on the table next to his bed, a bookmark stuck about two thirds of the way through _Tactics_. Kakashi stared at it for a moment. He never bothered to use a bookmark.

He lifted one of his arms, looking at the IV and various sensors attached. Even more concerning, a silver chakra-restricting cuff gleamed around his wrist. There was a matching one on his other arm.

Moving was an effort, but it didn't hurt. He was willing to bet that was the drugs speaking though. His mind was fuzzy enough he had to be on something. He frowned at the way his arm shook, then let it fall back to the bed. There'd be no escape from the hospital in his near future, glass-breaking or otherwise. He doubted he could stand without his face making a sudden and forceful acquaintance with the floor.

He tried to assess his physical state. His mouth was sore and dry, but that was to be expected. His entire body ached distantly, though nothing felt broken. He didn't have any casts or large bandages, which was always a plus. He felt exhausted, but not chakra depleted. Or at least, not exactly. He must still have chakra though, otherwise why the cuffs? He didn't know what was off, but something was. Something felt... _different_. Something that seemed to flicker at the corner of his awareness, obscured enough that he couldn't make it out.

There was no point in delaying the inevitable any further. With a shaky hand, he pressed the button to call a nurse.

Only moments later, Tsunade came instead.

~*~*~

Tsunade was glaring at him. That had to be a good sign. If he were dying, he hoped her usually brusque bedside manner would be slightly softer.

"What did you get yourself into this time?" she asked as she laid her hands on his chest, her bright blue chakra tingling as it scanned his body.

"Got hit by a jutsu," he said, his voice a dry rasp, quieter than a whisper.

"That much we'd figured out without you. Do you know _what_ jutsu?"

"No," he said, feeling his eyelids already starting to get heavy.

"You killed the missing-nin who used it?"

"Yes, ma'am."

"Let's hope the jutsu died with them."

"What did it do?" He knew he wasn't going to like the answer, but he needed to ask.

She frowned. "We'll talk about it later. For now, you need sleep."

He was pretty sure sleep was all he'd been doing lately. He wanted to argue, wanted to stay awake and get answers, but he couldn't. Not with how quickly the room was dimming and he was being pulled into darkness again.

~*~*~

He did rest, though it wasn't like he had much choice in the matter. He dozed off and on, waking for a few minutes whenever a nurse came to check on him.

The door opened, bringing Kakashi out of his slumber. He expected to see another nurse coming to poke and prod at him again, but this time it was someone different.

Umino Iruka stood frozen just inside the door and Kakashi blinked slowly at him in surprise. He wanted to grin. Iruka was better than a nurse any day of the week.

"You're awake," Iruka said after a moment, rubbing at the scar on his face, the slightest blush on his cheeks.

"Woke this morning," Kakashi said, voice still hoarse.

"Oh. That's good."

The beeping of the monitors echoed off the walls of the room as they stared at each other.

There were signs of exhaustion on Iruka's face, slight dark circles under his eyes.

"Are you okay?" Kakashi asked, before he could think better of it. 

Iruka glanced around, trying to find something to look at besides Kakashi. There wasn't much else in the room. "I'm fine," he said.

Kakashi watched him. He should say something. Thank Iruka for visiting. Tell him to come in all the way and take a chair. That'd be nice. But he couldn't work out what to say, not with sleep tugging at his consciousness again.

"Right," Iruka said, "I should let you rest. I was just here to... see someone. Someone else. And thought I'd stop by." 

Iruka's cheeks were getting redder. It was cute, Kakashi thought, mind a pleasant sort of fuzzy as his breath slowed and deepened. He wondered who Iruka was there to see. Hopefully they weren't injured too severely. It'd be nice to have Iruka there to visit him.

"Okay," Kakashi slurred out, reaching the end of the time he could stay awake far quicker than he would have liked, especially given his present company.

As he was drifting off, he thought Iruka took a couple steps closer.

"Take care, Kakashi-san," Iruka said quietly. 

A thread of warmth ran through his blood as sleep reclaimed him.

~*~*~

The following day he was able to prop himself up into something that vaguely resembled a sitting position and even stayed awake long enough to demand answers.

"What did the jutsu do?" he asked when he finally had Tsunade in his room again. This time she didn't put him off.

"Whatever it was, it caused your blood cells to vibrate at an ever-increasing rate until they tore themselves apart, basically destroying you from the inside out. I've never seen anything like it." 

Kakashi's eyes widened. If he hadn't felt it firsthand, he wouldn't believe something like that was possible. Medic-nin that became missing-nin were the worst.

"We attempted an exchange transfusion," she said, "replacing as many of your damaged blood cells as we could, but it didn't work. Each time we did it, the effects lessened for a while, then started to increase again. The jutsu had settled too deeply into your bones. All the new blood cells your body created were infected by it, and that infection spread to the donated blood cells as well." 

Breath shallow, Kakashi's mind whirled. The rattling buzz he'd felt on his rushed journey home was no longer present, so they had to have found some way to fix it. At least temporarily.

She studied him for a moment, then continued. "We destroyed your bone marrow then replaced it. We couldn't regrow an untainted version of your own in a timely manner, so we used a donor's instead. It was the only way we could counteract the jutsu."

"So it worked?"

Her mouth tightened. "That remains to be seen. You're staying here for observation for at least another few weeks until your immune system fully recovers, not that you'll have enough energy to do more than lie in bed anyway. After that, we'll see what happens. This isn't going to be a quick recovery. We can use jutsu to make sure the transplant takes and to speed things along, but there's no instant fix for something like this, and we don't have much precedent to go on. You need to be careful with physical activity and chakra usage until your strength is back and we know there are no lasting side effects."

He nodded. Definitely no daring hospital escapes in his near future then. "How long was I out?"

"Nearly three weeks. We kept you under until it seemed like we'd found something that was working."

Kakashi let out a breath. He'd guessed days, not _weeks_.

"Rest," she told him. It was a command, not a suggestion. She turned and walked towards the door. Right before she left, she yelled back, "AND ABSOLUTELY NO USING CHAKRA."

Kakashi snorted. With the cuffs on his wrists, that wasn't even an option. 

He stared at the door she'd forcefully shut behind her. What _had_ he gotten himself into?

~*~*~

It was another few days before he could do much more than push himself into a semi-sitting position, until even just thinking about picking up one of his books wasn't enough to make him realize how exhaustion still ruled his body. Whatever combination of drugs they were giving him, it was the good stuff. Directly after his doses, he floated in a haze that blurred the lines of awake and dreaming. Even between doses, the lingering fuzz of dulled senses remained.

But exhaustion retreated, grudgingly giving him more time awake, and eventually he managed to sit up fully and grab _Tactics_ from where it had been placed beside him. The other books were neatly stacked, but it laid apart from them like he'd been in the middle of reading it. 

It felt good to have one of the books in hand again. He opened it to the bookmarked page, curious. It was just a small slip of paper, not even two centimeters square, possibly torn off a blank scroll. Maybe in all the chaos, it'd slid in between the pages of the book and someone had figured he'd been using it to mark his place.

Shrugging, he put the scrap of paper on the table and closed the book. It wasn't where he'd left off. It wasn't even the right book. He set down _Tactics_ and grabbed _Violence_ , flipping it open to the last chapter he remembered reading.

His mind was still fuzzy from the painkillers, but he was lucid enough to read. He grinned and settled in. This was one of his favorite parts of the book. The big climactic action scene, not to be confused with the _Big "Climactic" Action Scene_ , which happened just after this battle, another of his favorites.

_Himeko saw the domed tower rising before her,_  
_standing tall and proud on the hard plains. A_  
_wiry bunch of plants grew just to the north of_  
_the impressive structure, only accentuating its_  
_massive size._

_"Phallic much?"_

Kakashi blinked. That had been Iruka's voice. Clear as day, as if he were sitting right next to Kakashi. Feeling more than a little stupid, Kakashi glanced around the room. No Iruka in sight. He turned back to his book, amused at the direction his mind had just taken.

_Himeko's chest heaved as her breath came in_  
_harsh pants, expansive breasts bouncing with_  
_each long stride she took, desperate desire_  
_twisting deeply in her core. She had to arrive_  
_in time._

_"Oh, I'm sure she'll arrive in time. Come in good time too," Iruka said with a snort._

Kakashi blinked again, and glanced around the room a second time. Still no Iruka. Okay, these painkillers were even stronger than he'd thought if they were making him hallucinate Iruka giving _Icha Icha_ commentary.

 _She hadn't had enough time to prepare for the_  
_battle she was about to face. The messenger_  
_had come just as she'd stepped out of her_  
_bath, rivulets of water streaming down her_  
_smooth skin as she stood, nipples hardening_  
_in the chilly evening air. She'd thrown on a_  
_short, silk yukata to answer the door. It_  
_clung to her skin as her serving girl gasped_  
_out the news._

It was all in Iruka's voice now. Every single word of it. Like he was reading the book aloud. Kakashi held back the giggle that idea brought up. _Iruka_ reading _Icha Icha_ to him. These were _definitely_ good drugs. Feeling his face heat, he continued reading.

_Her true love. He'd been taken. They'd_  
_captured him._

_Those short sentences were all it took to get_  
_her moving. There was no time to put on more_  
_clothing, just the short yukata covering her_  
_glistening skin. She hadn't even tied it_  
_properly, the shoulders slipped dangerously_  
_low, threatening to slide down completely_  
_with each shuddering breath. Only the_  
_moisture on the generous swell of her breasts_  
_stopped its downward motion. She felt cool air_  
_against the most delicate, sensitive parts of_  
_herself as she moved, a liberating feeling_  
_even in this harrowing situation._

_"Poor girl is going to fall out of her yukata at this rate." There was a pause. "If that's how she ends up defeating the bad guys, I swear to god, I'm throwing this book against the wall, Kakashi."_

Kakashi grinned. Himeko did defeat the bad guys, but not via a wardrobe malfunction.

 _She'd grabbed her sword, but there was no_  
_time to fasten it properly across her back._  
_The scabbard slapped against her firm,_  
_curvaceous ass with every step she took,_  
_driving her forward that much faster._

 _"It was a long, hard sword._ So hard. So long. _Perfect for thrusting into things. In long, hard thrusts. First in, then out, then in again. The hilt stood up proudly, just begging to be gripped with a firm hand," Iruka added in a dry voice._

Kakashi snickered. His imaginary Iruka had excellent commentary. He also read at a different pace than Kakashi. It was almost like reading the book for the first time all over again. 

Well, if it was going to be like that, he needed to do this right and take full advantage of the Umino Iruka-read audiobook that his imagination hopped up on pain meds was supplying.

Almost regretfully, he put down _Violence_ and picked up _Paradise_ , starting from the beginning. He was delighted to find that his imagination was more than ready for the task, giving him an audio track complete with commentary, though it was more hesitant at first. Kakashi could almost hear the embarrassment in Iruka's voice at the beginning, reading quietly like he didn't want anyone but Kakashi to hear. Kakashi couldn't hold back a gleeful giggle at that mental image. A few soft snorts and one or two " _oh dear god_ "s were all Kakashi got for asides in the first chapter. It wasn't until midway through the book that Iruka seemed to get into full swing, voice picking up confidence and sharp wit coming out in full force. 

The sex scenes were a particular treat. The first one had been read in a halting, awkward fashion, the dirtiest parts rushed through in a nearly inaudible whisper. The second one had been greeted with a loud sigh then read in a near monotone. The third one though, the third one was when things started to get good, and the fourth one had Kakashi squirming as Iruka's voice caressed each word, just a little deeper and huskier than usual, like he wasn't entirely unaffected by it either. The commentary had been kept to a bare minimum, but Kakashi hadn't minded. There had been one thoughtful, low _hmm_ right after the hero confessed his deepest desire to the heroine, of having her bend him over his desk and peg him, that had Kakashi's toes curling. It had been followed by a slight pause, then the sound of a throat clearing before the reading had continued. Kakashi had always liked that scene and he was glad to know that imaginary, book-reading Iruka did as well. There were a number of scenes that he couldn't wait to get to, especially one towards the end of _Tactics_ , but he wouldn't let himself skip ahead. 

He was so absorbed in it, he didn't realize how late it'd gotten until he looked up from the last page of _Paradise_ and saw how dark it was in his room. He vaguely remembered nurses coming in to check on him a few times. They were giving him smaller doses of medicine now, making him less groggy, but it was still enough to keep Iruka reading in his head. He hadn't paid them much mind and they'd eventually left, which was all he really cared about. 

Exhaustion hit him hard. Placing _Paradise_ back on the table by his bed took more effort than it should have. 

He snuggled down into his blankets, snatches of Iruka's voice still floating in his mind. His eyelids felt heavy, and he didn't try to fight sleep, instead letting his mind wander as he waited for it to take him. He wasn't surprised to find where his thoughts went. 

Hallucinations, drug-induced or not, were never the best sign, but he couldn't bring himself to care. If this is what his unconscious mind decided to do while he was under the influence, it was time well spent. Maybe it meant he'd been letting his fantasies get the better of him lately, a sign he'd been getting a little too attached, but there wasn't much he could do about it at the current moment. 

He'd always liked Iruka's voice. He liked a lot more than that, but Iruka's voice was definitely high on the list. More than once he'd hung out in the mission room when Iruka was on shift, just to catch little snippets of his conversations. Not that he'd admit it to anyone but himself. As far as everyone else in the village was concerned, they were simply two colleagues who'd shared students and were now on semi-friendly terms, nothing more. 

And sure, he might hit on Iruka a little from time to time as he picked up his missions and dropped off his reports. Or it might be more than a little, and perhaps more frequently than from time to time. But it didn't matter how much or how often, Iruka didn't notice. Kakashi wasn't sure if he was completely oblivious or just uninterested, but either way, Kakashi didn't push it. Flirting was enough. If he was being honest with himself, it was probably better that way. 

Kakashi shook his head a little. No point in dwelling on it. It was just a crush; it'd go away. _Eventually_. 

Besides, it'd helped him get through a day of bed rest so quickly he hadn't even realized it'd gone by. He might be stuck in the hospital for a while longer, but until then, he had some interesting, drug-induced material to keep himself entertained. _Very entertained_ , once he had the opportunity. He had every intention of rereading that fourth sex scene as soon as he knew a nurse couldn't walk in on him at any moment, especially not to check why the monitors said his heart rate was suddenly skyrocketing. 

He grinned to himself as he started to drift off. Tomorrow he'd read _Violence_ from the beginning. There were quite a few scenes he was looking forward to hearing in Iruka's voice. He hadn't thought there was a way _Icha Icha_ could be better, but he'd been wrong. 

His last thought before sleep was that Iruka could probably make _everything_ better. 

~*~*~

Two days later, they'd cut him off from the painkillers, and he was more than a little disappointed to find the hallucinogenic properties of the medication gave out abruptly about two thirds of the way through _Tactics_. He read a few more pages, but while he could force himself to imagine it in Iruka's voice, there was no more amusing commentary to go with it, and it just wasn't the same. _Tactics_ had always been his favorite in the series, but the last third of it felt boring now in comparison. He skimmed through the rest, but his heart wasn't in it.

For a brief moment he considered asking for another dose, one more should be enough to get him through the end of the book, but he didn't. He was still a little fuzzy from the last one, but he wasn't in pain. He couldn't imagine Tsunade responding well to "Listen, just give me one more dose. There's this scene coming up in about 50 pages that demands a cute, hallucinated chuunin read me the dirtiest parts. And could you maybe disconnect the heart monitor and keep the nurses out while I read it?"

His eyes caught on the scrap of paper that was still on the bedside table, and for one moment he wondered if maybe, _just maybe_. 

He snorted. Now he really was imagining things.

Still, just for the hell of it, he tucked the bookmark back into _Tactics_.

Shaking his head, he set it down and picked up _Paradise_ again. His memory was good enough, he could remember what he'd hallucinated. Maybe he didn't have the last third of _Tactics_ , and sure that was the best of the series, but he still had hundreds of pages just begging to be reread.

Grinning, he imagined a red-faced Iruka sitting by his side, casting worried looks at the door as he started reading the first chapter.

If he had to be confined to a hospital room, this was _definitely_ a good way to spend the time.

~*~*~

At the end of the two weeks, Kakashi had seven chapters mentally bookmarked for further perusal once he was home. He'd started skipping most of them during his rereads, his mind painting pictures of Iruka that were far too vivid to be thinking about anywhere outside the privacy of his own bedroom. The tiny hitches in his breathing, each quiet clearing of his throat, a few audible swallows, even some rustles like he'd been shifting in his seat. They all echoed loud and clear in Kakashi's head. He hadn't realized his imagination could be quite so _detailed_. He wasn't going to complain about it though, not when it'd given him words like _aching, throbbing, straining, writhing, thrusting, fucking_ in Iruka's voice, rough and low.

~*~*~

Tsunade ran test after test on him before she was willing to take off the chakra-restricting cuffs and let him go. He'd started to become suspicious of the amount of blood she'd taken from him, like she was trying to bleed him dry one syringe at a time. But each test came back negative for any remaining traces of the jutsu and slowly they allowed him more freedom. First letting him exercise, a nice way to work off steam after days of having nothing to do but imagine Iruka reading him porn, then eventually they let him use chakra again. Under the observation of roughly half of Konoha's medic-nin. He had a feeling more would be there, they just couldn't fit in the room.

It was anticlimactic. He'd half expected something to explode, possibly himself, the first time he gathered his chakra, and from the look on some of the medic-nin's faces, he hadn't been the only one. 

It felt _good_ to mold chakra again, to have the cuffs off and to be able to shape the energy of his body.

There was an audible sigh of relief from the assembled medic-nin as he walked up a wall, across the ceiling, and then back down the opposite wall with no issues.

They'd even brought out chakra induction paper for some reason Kakashi couldn't fathom. The moment he touched the paper it crinkled in the exact same way it always had, but that didn't stop a handful of the medic-nin from gathering around it, one of them even bringing out a magnifying glass to take a closer look.

Eventually Tsunade released him with a warning about taking things slow and only using minimal chakra until his strength had fully returned. She said he'd get tired quicker than usual for the next month or two, but he could start taking easy missions with no risk of enemy engagement once his strength was back. He had a standing weekly checkup with her, and was commanded to report any anomalies in his health, no matter how small.

Kakashi nodded like he understood and would follow her instructions to the letter, though they both knew otherwise.

Halfway home, _Icha Icha_ series in hand, a sudden urge to veer off the quickest path to his apartment hit Kakashi, a pull telling him there was somewhere else he needed to go first. His instincts rarely let him down, so he went.

It wasn't long before he saw Iruka sitting on a bench, looking out over the town. It felt right to run into him so soon, given how much Kakashi had been thinking about him, but that didn't mean he knew what to say.

Iruka blinked at him in surprise and got to his feet. "Kakashi-san, you've been released?"

Iruka's eyes flickered down to the books in Kakashi's hands and quickly away. There was a hint of pink on his cheeks. A shiver tried to run through Kakashi's body, but he suppressed it. Two weeks of near constant fantasies about Iruka reading him smut weren't doing any favors to his social skills. 

"Yeah," was all Kakashi managed to get out, glad he had a mask, otherwise it'd be clear he was blushing harder than Iruka.

"That's wonderful," Iruka said, genuine happiness in his voice and it made a pleasant warmth run through Kakashi's veins.

They stood there for a moment, staring at each other. Kakashi was hit by the urge to step closer. He pushed it down. His instincts might be good most of the time, but he knew when they were off.

He made his excuses and Iruka wished him well. His quiet "Take care" as Kakashi turned to walk away brought back the fuzzy memory of Iruka shuffling closer to his bed, whispering the same thing. It pulled Kakashi to a stop.

"Thanks for visiting," he said.

Iruka's eyes widened. "You remember?"

"Yeah. Is your friend okay?"

"Oh." Iruka blinked, his blush getting darker. "Yes. Everything's fine now."

"That's good," Kakashi said. They stayed there, staring at each other for a beat, then Kakashi made himself walk away, not sure what else to say. The entire way home, the only thing he could feel was a desire to go back to Iruka. He really was going to have to figure out how to get over this crush.

~*~*~

Kakashi recovered quickly after his release. His release from the hospital, that was, not any other, more fun and life-affirming kind of release. Though the one of that nature caused by his first post-hospital reading of the fourth sex scene in _Paradise_ also had a refractory period short enough to put most 18-year-old boys to shame.

Some people might feel guilty for getting off to the idea of a respected member of the shinobi community reading them porn. Kakashi was not one of them.

His weekly checkups with Tsunade were uneventful no matter how many tests she threw at him. She let him go back to his regular workout routine, though she did repeatedly remind him to inform her if anything abnormal happened during training. He was fairly sure she wasn't referring to Gai, so he kept all oddities of that nature to himself. 

Getting her to let him take on his usual missions again was another matter altogether. It took far longer than he could call justified before she okayed his return to active duty, especially considering the fact that he'd shown no side effects from the jutsu. But finally she did allow him to take missions again, even if it was only semi-active duty.

"B-rank at least," he tried, not for the first time.

She stared at him blankly. "Maybe we should start you out with D-ranks," she said after a moment.

"C is fine." Kakashi gave her his best eye-smile to show exactly how okay C-ranks were. There was no way he was getting stuck on a bunch of D-ranks when he didn't have a team of genin to do the worst of it. 

He excused himself quickly, getting out of Tsunade's sight before she could decide D-ranks were the way to go.

Who knew, maybe he'd get lucky and get assigned another very-much-not-a-C-rank mission. A jounin could always hope. He might be able to bribe the mission desk workers to give him the closest thing to a B-rank they had. There were always a few missions that never fit neatly into one rank or another.

Kakashi grinned. Being on (slightly restricted) active duty again meant regular trips to the mission room. He'd never thought he'd be this excited for paperwork. Paperwork, and the people who collected it.

~*~*~

As it turned out, he wasn't lucky. The mission desk workers had clearly been warned that C-rank meant _C-rank_ and definitely not almost-B. They gave him a mission that involved clearing about a dozen trees from a lot just north of the Academy that was going to be developed. If anything, it was a D-rank masquerading as C-rank, classified as such for the simple fact that no one trusted newly made genin with large amounts of explosives within the walls of the village.

There was also a disappointing lack of anything resembling a pony-tailed chuunin in the mission room. To be expected, given that it was a school day, but stranger things had happened. Though, those stranger things usually involved Gai. 

Between the mission and the person who wasn't there to hand it over, today was not Kakashi's day. At least they were going to let him blow some things up. Maybe if he tried hard enough he could pretend the trees he'd be demolishing were enemies. Very slow, dim-witted enemies that just stood there as explosive tags were carefully attached to them in a way that would ensure all resulting debris was contained within an acceptable perimeter. 

Kakashi had a good imagination, but it wasn't _that_ good. He didn't even think Tsunade's drugs would help. It was going to be a long day.

The only plus Kakashi could think of was that he'd be working near the Academy. Close enough that he might conceivably drop by just because he was in the neighborhood. To check on the future of Konoha and all that. There was also a chance that he could possibly run into some unspecified teacher on their way home for the day and casually suggest that a bowl of ramen could potentially be in order. 

Not that he was going to do any of that. It was just nice to know he had options. 

On the other hand, being just a few blocks from the Academy and all the possibilities it offered was _distracting_. To keep himself from dwelling too long on things that weren't going to happen, he mentally recited a few of his favorite _Icha Icha_ scenes. He'd reread the books so often in the last few weeks, he could easily recall his imaginary Iruka's commentary.

And so he got to work, as Iruka's voice caressed words of passion and love. And more than a little abuse of ninjutsu.

 _With chakra vibrating his hand, his signature_  
_O no Jutsu, he trailed his fingers up her thigh,_  
_loving the way her legs shook and her nails_  
_dug into his muscled biceps as she clung to_  
_him with desperate passion._

_There was a long pause. "Wait. Is this why Naruto accused me of not teaching the "interesting stuff," then went bright red and refused to say another word for a full ten minutes?" Kakashi could imagine Iruka shaking his head. "It was the longest I'd ever seen him be quiet."_

_"How do you want me?" Miko asked, her voice_  
_as hot as he knew it would be inside her._

 _"On the ceiling," he said as he pulled her_  
_closer and leapt up, releasing chakra through_  
_his knees to anchor them there._

_Iruka snorted. "Sure, ceiling sex is all fun and games right up until you remember that 99.9% of ninjas lose control of their chakra when they orgasm. The hospital should have sent Jiraiya the bill every time someone came in with a broken dick after they fell eight feet onto it."_

_"And I mean, don't even get me started about how difficult it is to release a steady amount of chakra through your knees even under normal circumstances."_

Kakashi had to admit that imaginary Iruka was right. Not that he'd ever tried to see if it were possible. Absolutely not.

He fell into a rhythm, exploding a tree with tags, then sorting the resulting pieces into piles by size, which would be collected later by genin teams on actual D-rank missions. The work was as boring as predicted, though it was still better than no missions at all. Even if he was sure Tsunade had handpicked it herself, punishment for the dozen or more times he'd done everything but beg to be put back on active duty after she'd repeatedly told him not yet. Besides, Iruka commenting on Hiiro's apparently endless stamina made it go fast enough to not be completely maddening.

Compared to Kakashi's normal missions, this was on the easy side, but it used more chakra than he'd expected. Mostly because he was using jutsu instead of physical labor whenever possible. It wasn't laziness, he told himself, he just needed to test his limits and make sure he was back in top form. As far as he could tell, he was close. He was using chakra a little faster than normal, but not at an unreasonable rate. 

He finished in a decent amount of time, and then headed to the mission room to turn in his report. That was when his luck seemed to improve. Iruka was on shift. Kakashi knew he'd be there even before he entered the room. It wasn't that he'd memorized Iruka's schedule, it was just that deep inside of himself, he _knew_ who he'd see behind the desk. It felt _right_ going there. If Kakashi's instincts had been good before, they were now on an entirely different level.

As he walked into the room, he felt... he wasn't exactly sure. A little lightheaded, maybe. Perhaps being outside most of the day and using more chakra than he had in weeks had drained him more than he'd realized. But it didn't feel like exhaustion or heatstroke. It felt like excitement, anticipation. He'd gotten flustered around Iruka before, mostly when Iruka had given him an offhanded compliment or had just looked at him for a moment longer than normal, but this seemed different somehow. It wasn't just his heart beating a little faster, his face feeling a little hotter. It was a restlessness just under his skin, a sort of nervous energy that he wasn't sure he could blame entirely on Iruka. He couldn't quite put his finger on what it was, but it seemed to build as he got closer to the desk.

Overly aware of his body as he walked up, he felt his chakra shift almost imperceptibly as he handed over his report to Iruka. It jumped and crackled, bridging the small gap between their fingers. The sharp snap and tiny jolt of electricity caused them both to jump.

Iruka laughed, but Kakashi couldn't do the same, too embarrassed by what had just happened. He opened his mouth to apologize, but Iruka headed him off.

"It's been so dry lately, I'm surprised that doesn't happen more often."

Kakashi frowned slightly, but nodded in agreement. It'd been such a small spark, Iruka probably hadn't noticed the difference. Maybe only a sensor would have. But it hadn't been static electricity, it'd been chakra. For one brief moment, he hadn't had control and it had jumped out at Iruka.

Kakashi beat a hasty retreat out of the mission room, mumbling something he hoped could be taken as a polite goodbye as he did so. All of Tsunade's warnings tumbled around in his head. If anything seemed strange, if anything went wrong, go straight to her, tell her immediately. The jutsu might be reemerging from some long dormant state. It might start ripping apart his cells once more.

He could still remember all too clearly the way his body had shaken, the ripping feeling, the tremors and pain. This hadn't been like that. It'd been warm and momentary. A fleeting spark with just the barest suggestion of loss of control. It hadn't felt wrong. If anything, he wanted to test it. To go back to Iruka and reach out towards him and see if it'd happen again. But he didn't.

If there really was something wrong with his chakra, there was more than one way to find out. 

By the time he reached an open training field, he could almost believe he'd imagined the whole thing. He felt completely normal. Maybe a little low on chakra after his day of work, but nothing a good night's sleep wouldn't fix. Possibly his crush really was growing to a ridiculous level and it was making him more flustered than ever before. That combined with all of Tsunade's warnings and a long day of boring work might have just assembled into some bizarre delusion.

Still, he needed to make sure his chakra wasn't acting strangely. If anything felt off, he'd tell Tsunade, but there was no point in bothering her if he'd just been flustered over a cute scar and a pair of warm eyes.

The basics were easy enough to run through. He whipped through half a dozen jutsu in a blink of an eye. Nothing felt wrong. His chakra was doing exactly what it was supposed to be doing. The rattle and shake of his cells was nothing but a memory. 

Feeling sure of himself now, he moved on to higher level jutsu. His Raikiri was perfect; bright and sharp and deadly. He released it after a moment, the air around him fading to silence. An earth wall and a water clone also caused him no problems. Neither did a genjutsu or summoning Pakkun, though the latter did get him a rather unimpressed look when he explained he was just running through a few jutsu and Pakkun was free to leave. 

Pakkun sat and stared at him.

"I'll buy you steak later?" Kakashi tried.

Pakkun continued to stare.

"Now?" This seemed more acceptable. "Let me just do one last jutsu."

Kakashi made a tiger hand seal then blew out a large ball of fire. Only it wasn't just large, it was _gigantic_. 

Pakkun flattened himself to the ground, narrowly avoiding a severe case of singed coat syndrome, while Kakashi jumped back in surprise. He hadn't planned on making the katon quite that big. 

Kakashi blinked the afterimage out of his eyes. Nothing had felt wrong, it'd just been more powerful than he'd intended. He'd always been decent with fire, but not _that_ good. Producing a katon that size should have taken a fairly large amount of chakra, more than he'd gathered at the moment, but he hadn't used more chakra than he'd meant to.

Pakkun stood again, shaking himself. "Two steaks," he said gruffly.

Kakashi nodded. That seemed fair enough.

They left the training field, Kakashi lost in thought. He didn't think he needed to tell Tsunade about this, not yet. She'd probably just laugh at him if he came to her saying he'd made a jutsu more powerful than he'd intended. He must have just put more chakra into it than he'd meant to, that had to have been the case. Nothing else made sense.

By the time they got to his apartment, Kakashi had pushed it to the back of his mind. Surely any side effects of the jutsu reawakening would be much more sinister. What missing-nin would want to make their opponent stronger, after all? With that settled, Kakashi started grilling Pakkun's steaks.

~*~*~

The decision not to tell Tsunade about his paranoid theories turned out to be the right one, because next he was assigned a messenger mission. Still only a C-rank, the reports he was carrying were far from top secret, but for the first time in months, he felt like he was truly stretching his legs.

Running through Fire Country, doing something productive again, it felt good. Or at least it did, right up until he was making his way home and a sizable portion of the forest around him exploded.

Apparently his plan to get a not-actually-a-C-rank mission had gone a little _too_ well.

His eyes were nothing but afterimages of fire and explosions, his ears all ringing and reverberations from the blast as a missing-nin attacked him. Kakashi hadn't seen him before, but the missing-nin clearly knew him. 

He was good, easily jounin level and with long-range attacks ideal for keeping Kakashi far enough away that he couldn't use his specialties. But Kakashi was nothing if not resourceful. He hadn't copied a thousand jutsu for nothing.

A part of Kakashi reveled in the fight. It'd been too long since he'd last been in the thick of battle, since he'd felt the way his heart pounded, his senses sharpened, his muscles burned. Kakashi never went out looking for fights, but there was no denying he was good at this. He'd been all but born to do this, and even after months of inactivity, Kakashi's body still remembered exactly what it needed to do. The muscle memory of battle was carved so deeply into him, had been since he'd been old enough to hold a kunai, Kakashi wasn't sure if it would ever truly fade.

Kakashi was unrelenting in the fight. He'd just spent far too long in the hospital, this would not be landing him back there. That more than anything motivated him. He blocked the missing-nin's long-range fire-based attacks with earth walls and sent clones to scout the area, occasionally throwing out a long-range jutsu of his own. He'd never been fond of them, they were often a waste of chakra since the distance from the target made them more likely to miss. 

The missing-nin's attacks were powerful. Even behind his walls of earth, Kakashi could feel the heat of them. Trees lit up like matches as fire rained down around him. 

But Kakashi didn't give an inch. He methodically tested the missing-nin until he found a weak spot. It seemed his jutsu had a reset time of 30 seconds between attacks, more than enough for Kakashi to exploit. 

Kakashi judged his chakra reserves. Even after using the Sharingan, he had a little less than fifty percent. It'd decreased slightly faster than it normally would have, but he'd expected that and worked it into his plan. He still had more than enough chakra to see this through.

The missing-nin attacked again, and Kakashi let a clone take the worst of the fiery blast, then he closed the distance between them. 

His opponent's eyes narrowed and Kakashi could see from his expression that this not how he'd wanted this battle to go.

Keeping his eyes on the missing-nin, Kakashi pulled deeply on his chakra, letting a Raikiri form in his hand, preparing for an attack.

But that was when he felt it, felt the way the Raikiri was... _different_ , somehow. His own jutsu felt foreign in his hand. His lightning chakra had always flashed and sparked against his skin, but now it was more than that. It didn't just flicker and crack, it _seared and scorched_ , an all-consuming heat combined with its electric spark. 

Unsure of what was happening, he risked a glance at his hand. Shock froze him and he found himself unable to turn his eyes away. Tendrils of flame licked their way around his hand, dancing with the lightning, at times seeming to wrap around the lightning and strike out with it, at others seeming to propel it forward on the burst of an explosion.

He knew he needed to move, needed to attack, but all he could do was stare at his hand. At the Raikiri, if it could be called that anymore. Even the sound of it was different. The chittering so similar to birds was still there, but there was a crackling behind it now, a muted roaring that spoke of raging forest fires just out of sight.

It was unsettling, unnerving, that a jutsu he'd used so many times, a jutsu he'd _created_ , could suddenly be so different without him doing anything to it.

Kakashi might have frozen in shock, but the missing-nin had not.

The attack came, quick and furious, and Kakashi's instincts kicked in. He dodged then struck in one fast, fluid motion. The missing-nin barely had a chance to register his surprise as the Raikiri pierced his chest. At least it still did what he needed it to do.

Kakashi destroyed the body quickly, then left the area, not wanting to get caught by any friends this missing-nin might have had. He didn't go all the way home just yet though.

Once he was within a short distance of Konoha, he stopped. His reserves were low, but he needed to test this, needed to figure out what it was even if it did waste chakra in the process. He was close enough to Konoha that it shouldn't matter, there shouldn't be any more missing-nin.

He held out his hand in front of him and gathered his chakra to create another Raikiri. The first few sparks of lightning seemed normal, but as he drew deeper on his reserves, he felt it: The other chakra, one that wasn't his own. Flames joined the lightning and flickered hot between his fingers, but they didn't burn him. If anything, there were more flames now than there had been before.

He could feel the pull on that foreign chakra, exactly like the pull on his own, but deeper, underneath it. He had a decent mastery of fire, though he used it less than most Konoha shinobi did. Even setting his lightning affinity aside, earth and water came more naturally to him than fire ever had. He knew some high level fire jutsu, but he'd _never_ been good enough with it to do something like this. He'd never been anywhere near the point where he'd be able to shape it into a signature jutsu like he had with lightning.

This shouldn't be happening, he shouldn't be able to do this. Shinobi didn't just randomly develop new chakra affinities. 

As much as he hated to admit it, this qualified as "something strange." It seemed like their treatment did have some side effects after all. There was no putting it off this time, he needed to talk to Tsunade.

~*~*~

Given the situation, going straight to Tsunade would have made the most sense, but Kakashi was never one for going directly to somewhere he could wander. After all, the scenic route was the best way to experience the road of life. And if said scenic route happened to cross paths with certain people with adorable nose scars, who was Kakashi to refuse? Besides, he'd been getting far too predictably late with his reports. Turning one in the moment he got back to the village would be a nice way to keep the mission room workers on their toes. Really, he was doing this for their sake.

As he got closer to the Tower, he could feel his chakra starting to move, that restless shift beneath his skin again. It only increased as he climbed the stairs to the mission room. He shrugged his shoulders, but it didn't help. His chakra felt excited, agitated, ready for something, though Kakashi didn't know what. 

His body auto-piloted into the shortest line in the room while he tried to analyze what he was feeling. There was a strange, uncontrolled buzz to his chakra. It didn't feel the same way the jutsu had, it didn't feel destructive, it wasn't painful. He didn't feel like his body was trying to rip itself of part again. It was odd, sure, but it wasn't uncomfortable. There was something about it that he couldn't quite place.

"Kakashi-san, your report please."

Kakashi was too good of a ninja to jump, but he nearly did. He also should have been good enough to realize he'd reached the front of the line, but apparently he wasn't. 

Iruka stared up at him. Kakashi didn't fumble, but he also couldn't say he was particularly smooth as he reached into one of his pouches to pull out his mission report.

"You're early," Iruka said with a warm, amused smile as he held out his hand for the report. 

Kakashi's chakra shivered up his spine. He didn't let himself shudder at the thrill of it, instead handing his report over to Iruka.

The rush of chakra into his hand took him by surprise. The sharp _crack_ of electricity between their fingertips echoed in the room. It was loud enough the chuunin sitting next to Iruka looked over in curiosity. Iruka dropped the report and shook out his hand, inhaling sharply. 

Kakashi stared at Iruka's hand in horror. There was no way he could pretend it was static electricity this time. There'd been too much chakra in that spark. Iruka had to have felt it, even a newly minted genin would have been able to feel it. 

He could still feel his chakra moving in his body, but it'd settled a little, seeming more grounded now.

Iruka looked up at him, a furrow creasing his brow, just a hint of concern in his eyes. 

"Ah, sorry about that," Kakashi said, grasping for a reason, any reason, he'd just lost control of his chakra. "I was messing around with a new lightning jutsu on the way back and it seems to be having a few side effects." He rubbed at the back of his neck. It wasn't a complete lie. 

Iruka frowned for a moment longer, than plastered on a smile that didn't reach his eyes. "Aiming for 2,000 jutsu instead of just 1,000?" he asked in a rough approximation of a joke.

Kakashi let out a huff of what he hoped would be construed as laughter, and forced his eye into a smile of its own. "Well, you know what they say about variety and spice and all that."

They lapsed into silence, staring at each other, both trying to out "Nothing to see here" the other. 

The ninja waiting in line behind Kakashi cleared his throat. Both Kakashi and Iruka jumped. So much for being too good of a ninja to jump in surprise.

"Thank you for your hard work on this mission, Kakashi-san," Iruka said. He hadn't even looked at the report yet.

"Right. You too," Kakashi said, then mentally kicked himself. Iruka hadn't been on a mission.

He didn't flee. Kakashi was one of the best jounin in Konoha. He _did not_ flee. Especially not from chuunin armed mainly with paperwork. He did, however, take the moment to practice his speed. It was always good to know exactly how quickly one could exit any given room. As it turned out, Kakashi could leave the mission room with highly impressive levels of speed.

Two hallways later, he stopped his definitely-not-fleeing. He took a deep breath and sagged against the nearest wall. A passing office-nin with arms full of paperwork gave him an odd look, but let him be.

That could have gone worse, he told himself. There had to be ways that could have gone worse. Hundreds of them, he was sure. Gai could have been there, asking Kakashi at the top of his lungs if that had just been A Spark Of Youthful Passion. Genma could have been there and ended up choking on his senbon from laughing hysterically at Kakashi. Naruto could have been there, hauling Iruka to safety from whatever weirdness Kakashi was clearly infected with. It definitely could have been worse. 

Kakashi took a moment to try to figure out what his chakra was doing, but as soon as he focused on it, he realized it felt completely normal again. Nothing felt odd, there was no shifting, no unexplained movement to its flow. If it weren't for the fact that he could still feel the hot burn of a blush under his mask, he might be able to think he'd just imagined the whole thing. The sharp tingle in his fingertips from the shock told him otherwise.

He needed to talk to Tsunade. Something wasn't right and he had to get it under control before he accidentally hurt someone.

Squaring his shoulders and facing the inevitable, he headed to her office.

~*~*~

**Notes for the Chapter:**

> Thank you for reading! I hope you liked it so far! Chapter 2 will be basically the rest of the fic. It just needs some editing, so I should have it posted by next week.


	2. Chapter 2

For once, Tsunade didn't keep him waiting. He was shown into her office immediately. The benefits of having something bizarre happening to his chakra, he supposed. 

She looked at him as he entered, question clear on her face.

"About those side effects," Kakashi said. "Is uncontrollable chakra one of them?"

She raised an eyebrow at him. "Uncontrollable? You feel it becoming agitated again?"

"Yes," he started. Tsunade opened her mouth but he headed her off, knowing she was going to assume the jutsu was making a comeback. "But not like that, not like the jutsu did. It hums, not rattles. And apparently I have some kind of sub-elemental affinity for fire now."

She made a face. "We were afraid of that."

"As in, you knew this could happen."

"Ninjas don't need bone marrow transplants often, but when they do, we can get around a lot of issues civilians face with them. However, we do try to match chakra affinity and blood type. Ideally, we'd use a family member. Your lightning affinity was also an issue. It's just not common enough in Konoha to give us a decent pool of donors, especially not with the time sensitive nature of the whole thing. So we decided to go for an affinity that was neither weak against nor strong over lightning to limit any potential complications."

"So, fire."

"That or water, but fire is more common so we had a larger pool of potential donors, and there can be issues with water and lightning, so..."

Kakashi gave her a flat look. They hadn't chosen water because they'd thought he might accidentally electrocute himself. Lovely. He had used lightning with water before just fine, thank you very much. He didn't bother pointing that out though, instead asking the more important question.

"Why didn't you tell me?"

"I did say there could be side effects and to be careful with your chakra until we were sure everything was back to normal."

He huffed. Telling someone there might be side effects wasn't the same as saying hey, just so you know, you might have entirely different chakra with a new affinity inside of you now. "I thought you meant from the jutsu."

She shrugged. "We weren't sure the donor's chakra would transfer. It would have been pointless to tell you if there were no such results. You would have been looking for things that weren't there. Even when DNA is graphed into a subject, like with Yamato, it doesn't necessarily mean the foreign chakra will take or that the shinobi who received it will be able to use it."

"What does this mean for my chakra?"

"Most likely, you'll continue to have both types in your system. It won't act like a bloodline limit, if that's what you're asking. The two types of chakra won't combine in the same way that would allow. In all the research we consulted, there weren't any cases of that happening. But you might be able to manipulate fire better now than you did before."

He nodded, he'd already noticed that was the case.

"Theoretically, you'll also be able to use them together better than most people. There weren't many cases to go on, but that seemed to be the general consensus."

"Is there a reason the fire affinity seems to come to the forefront as my chakra stores decrease?"

She looked interested and calculating in a way that made Kakashi fear for all the tests she was suddenly planning to run on him. "If the donor were to have better stamina or chakra regeneration than you, that might transfer with their chakra as well, though only for theirs, not yours. If you start out with, let's say, 90% of your chakra and 10% of theirs, then use half of it, theirs might fully recover long before yours, making the percentage of the secondary chakra in your system higher than normal."

Kakashi nodded again. That fit with what he'd been experiencing so far, but if things like stamina and recovery time could be transferred, other things might as well. "If the donor has any chakra tricks, will I be able to do them?"

"It's possible, especially if you can learn to mold the two types separately."

"And clan hiden jutsu?"

"Also very likely."

"Who's the donor?" Kakashi asked. He'd asked her once before, while he was still in the hospital. At that time, she wouldn't say, but the fact that Kakashi now carried the donor's chakra should change things.

"They asked to remain anonymous," she repeated.

He grimaced. "Did they know this could happen?"

"They knew there might be side effects."

"They knew I might end up with some of their chakra, not just their bone marrow?"

"They did and were okay with it."

He refrained from pointing out that the donor had apparently been given significantly more information than he had.

Another theory crept into his mind. "Will there be resonance? With the donor, or the donor's clan?" 

Ninjas with similar chakra occasionally felt it resonate when they were in close physical proximity to each other. It was most common among direct relations; parents and siblings, grandparents and grandchildren. Even one step away, with aunts and uncles or cousins, it was less likely for that familial resonance to be felt. To feel it with someone unrelated was all but unheard of. 

Tsunade studied him, recognizing the fact that he was fishing for more information. "It might. It would likely depend on how much of the donor's chakra was in your pathways at any given moment."

"So right after the transplant, there wouldn't have been much, but as it took and the amount of the donor's cells and chakra increased, the effect would also increase?"

She eyed him flatly. "Have you been having other side effects?"

Kakashi thought back to the shocks he'd felt as he'd handed over his reports to Iruka, the way his chakra had seemed to be acting up as he got closer to the mission room. The first one had been the first time his chakra had felt noticeably different, when it had first done something he hadn't meant it to. It was different from the warmth he had always felt around Iruka before, but it wasn't unpleasant. If anything, it felt _familiar_ , the warm buzz of home. Resonance was something Kakashi hadn't felt in years, something he'd almost forgotten even existed.

"Umino Iruka," he said. "He's the donor."

Tsunade gave him another flat look. "The donor wishes to remain anonymous." 

He didn't need her to confirm it, he knew it was true.

"Is there a limit to how much of _the donor's_ chakra I'll end up with?" he asked.

Tsunade shrugged a shoulder. "You're a test case here. My best guess would be it will remain a lesser amount to your own chakra and it will stay a secondary affinity. Any side effects you're feeling might also fade with time as your body gets used to having both types of chakra. They might be more noticeable now because they're new."

He could try to push her on it, but he doubted she'd give him anything more.

She did end up getting out chakra induction paper, and suddenly Kakashi realized what the medic-nin had been doing all those weeks ago. The paper wrinkled as always, but this time the edges smoldered, glowing a bright red before turning to ash. Kakashi stared at the paper. This was going to take some getting used to.

Tsunade also collected some blood to run more tests, but she didn't seem to think anything of note would be found. 

"It just wouldn't be a visit to you without losing a little blood," he said and she grinned at him, as sharp as her needles.

While he waited for the results, he considered what he wanted to do about Iruka.

~*~*~

Lying in wait outside the Tower was decidedly stalkerish, but Kakashi wanted to have this discussion and he wanted to have it as soon as possible. So he leaned against a wall and waited, book in hand. More than one shinobi shot him a suspicious look as they passed, though given his usual reading material, general reputation, and recent out-of-commission status, that was to be expected.

He got through three chapters of _Paradise_ before his favorite mental audiobook reader finished his shift and left the Tower. Kakashi wasn't surprised by Iruka's appearance, his chakra had been growing more restless for the last few minutes, the time it took Iruka to climb down the stairs and walk outside.

Iruka, however, did look surprised when Kakashi fell into step beside him. 

"Kakashi-san, can I help you with something?"

"I was hoping you could help me solve a puzzle I've come across."

"If I can be of assistance."

"I'm trying to figure out why someone would save another person's life, then insist that their good deed remain anonymous."

Iruka's step faltered for a fraction of a second, but he caught himself quickly. He cleared his throat. "Possibly they think they did what anyone else in their place would have done."

"But it wasn't anyone else who it did, it was them. Shouldn't that deserve recognition?"

"Maybe they don't feel it was something that needs any special acknowledgment."

"But what if the person they helped thinks otherwise?"

Iruka's left eye twitched and his voice grew sharper. "Perhaps they didn't want anyone to feel like they owed them something."

"I wouldn't-" Kakashi started to say, but Iruka gave him a skeptical look and he changed directions. "Okay, maybe a little."

"Of course, this is all theoretical. Everyone would have their own reasons."

Kakashi took a few quick steps and stopped in front of Iruka, forcing him to come to a halt as well. The action drew them closer together and the hum of Kakashi's chakra increased at the proximity. 

"Theoretical? Really?" He reached out and almost touched the bare skin of Iruka's forearm. Just as he'd expected, a shock jumped between them. Iruka started. It was smaller than earlier that day, but still clearly not static electricity. "Tell me you didn't feel your own chakra in that."

Iruka let out a breath, his cheeks stained red, then he nodded. "Yeah, I felt it. I felt it before too. Not the first time, but today it was impossible not to notice."

Kakashi stepped back. He realized as he did that his chakra had calmed down, like the shock had equalized it somehow. It still buzzed inside him, but now it was closer to the familial resonance he'd experienced many years before.

They fell into silence as they started to walk through the village again. 

"They have a list," Iruka said after a few moments. "It matches high risk shinobi with potential donors of much lower risk levels, just in case of emergencies. You are apparently one of the highest risks."

Kakashi snorted, of course he was. 

"There are about half a dozen of us matched to you, in case you come back with massive blood loss. Apparently having the same donors every time decreases the chances of these sorts of side effects. Though Tsunade-sama said that ones from blood transfusions usually only last for a few days, and considering the state most shinobi are in if they do need a transfusion, the side effects often pass while they're unconscious."

"You've always known it was me?"

Iruka shook his head. "Not at first. Only that I was matched with _someone_. But the few times I was called in to do extra donations, the second-in-command on your missions always turned in your reports. It wasn't hard to figure out."

Iruka seemed to be considering what he wanted to say next, so Kakashi waited.

"One of the criteria for this was that it needed to be unlikely we'd ever run a mission together. Also, same blood type and compatible chakra affinities. I checked all those boxes. I don't know who else you're matched with, or if Tsunade-sama asked someone before me, but I think anyone would have done it. I was probably just the first she asked."

"Thank you," Kakashi said, and Iruka nodded. Kakashi felt like he should say more, but he didn't know what. Instead he asked, "So, fire affinity?"

"Yeah, I know," Iruka said wryly. "Everyone assumes I have water affinity because of my name."

"No," Kakashi said, shaking his head, "fire suits you." Iruka embodied the Will of Fire. Between that and his often fiery personality, it was a more than fitting affinity for him. 

Iruka grinned a little, looking pleased by the statement. "So, you ended up with some of my chakra after all?"

"Yeah, though it took me a while to notice," Kakashi said. A sudden thought hit him. "Actually, I think I felt it. That day you stopped by my hospital room. I was mostly asleep, but I think that was the first time I felt your chakra."

Iruka stared at him for a moment, their eyes locked, then he looked away. His cheeks were still pleasantly pink. 

"Oh," Kakashi said, "that day. You were still recovering from the donation, weren't you? That's why you looked tired."

"Yes," Iruka admitted, "but it wasn't bad. Obviously I recovered a lot quicker than you did."

"Maybe," Kakashi allowed, "but I did get some new skills out of the deal."

Iruka snorted. "Like what? Sudden urges to grade piles of papers? An irresistible desire to file things? Oh, is that why you turned in your report early today?"

Kakashi chuckled. "A little better than that. Here, let me show you." He nodded his head in the direction of the nearest training field, only then noticing how far away from the Tower they'd walked.

Once they were on the field, Kakashi took a few steps away from Iruka and formed a Raikiri. The pull on the secondary chakra wasn't as deep this time, now that Kakashi's own chakra had been replenished during the last few hours, but it was still there, flames still jumped between the lightning.

Iruka's eyes widened, clearly recognizing his own chakra in Kakashi's signature jutsu. 

Kakashi let the chakra he'd gathered slowly disperse back into his system. 

"Definitely not improved paperwork," Kakashi said.

"I don't know," Iruka said, "it could still happen." 

Kakashi laughed. "Don't get your hopes up."

"Shh, let me have this for just a little while longer."

Kakashi grinned at him."Only if you'll train with me." It was spur of the moment, but it felt right.

Iruka sputtered. "Why?"

"I want to know what your chakra can do." 

Everyone's chakra was different. They all had quirks and tricks that made theirs unique. Without guidance, finding those things out would be a puzzle full of blank pieces. He might also want an excuse to get closer to Iruka, but he wouldn't say that just yet.

"You seem to be doing just fine without me, maybe even better than what I can do with it."

Kakashi shrugged. "That wasn't intentional. I want to know how I can use your chakra. What tricks there are to it."

"I don't have any tricks."

It was Kakashi's turn to give Iruka an incredulous look.

"Okay, maybe I have a few."

Kakashi grinned.

"I don't know how any of them are going to help you though."

"We'll see."

Iruka just shook his head, grinning back. "I guess we will."

~*~*~

_She stared deep into his glittering, cerulean_  
 _eyes, lost in them like a sailor lost at sea. His_  
 _gaze never wavered, piercing deep inside her._

_"I think of none other than you," he said. "Tell_  
_me how I can convince you of my loyalty."_

_"Say my name," she said. "Tonight, as you_  
_make love to me, the only word I want to hear_  
_from you is my name, over and over again."_

_He kissed her hard, breaking off only after_  
_she'd lost her breath. Kissing his way over to_  
_her ear, his breath hot against her skin, he_  
_opened his mouth to say-_

"Kakashi-sensei!" Iruka greeted, causing Kakashi to start.

He cursed himself internally, realizing too late that the building excitement he'd been feeling as he read was his chakra reacting to Iruka getting closer. He should have felt Iruka coming, not let himself be distracted by the things he'd been imagining in his head.

Iruka was carrying a box of supplies and his eyes flickered briefly to Kakashi's book, but he didn't comment. Instead he grinned, warm and genuine enough it would have caused a shiver to run through Kakashi even without this odd resonance that was happening between them. "You're early."

Kakashi shrugged, a little embarrassed. He might have kept Team 7 in a constant state of waiting, but he wasn't going to be late for Iruka.

When Kakashi had thought about training with Iruka, he'd figured it'd be outside, at one of the training fields, not in a meeting room in the Tower with no weapons in sight. But this was where Iruka had suggested they meet, so here Kakashi was.

"Let's get set up in here," Iruka said as he walked into the small room. With his chin, he gestured for Kakashi to take a seat. "We're going to start with something easy."

Kakashi shrugged and sat down, eyeing the box of supplies.

Iruka started pulling things from it, spreading them out on the table. Let it never be said that he wasn't a teacher to his core. He'd come to their first training session _prepared_. Kakashi wanted to tease him about it, maybe ask if he'd planned a full curriculum or written out lesson plans, but he didn't. He didn't think they knew each other well enough to joke around about something that was so clearly important to Iruka.

Iruka pulled out a stack of paper from his box, followed by multiple wells of ink, a few small, clear bowls, and two sets of brushes.

Kakashi laughed nervously. "This isn't some elaborate trick to get me to write cleaner mission reports, is it?"

"I can multitask," Iruka said with a grin, but he wasn't looking at Kakashi, instead focused on his supplies.

Kakashi shifted in his seat. His chakra was still in that oddly overactive state it got when he was first around Iruka.

"I want to see how this goes and then we can try the more interesting things." Iruka opened a bottle of ink and poured a little into two of the bowls, just enough to wet a brush a few times.

Kakashi blinked, but he wasn't seeing things. The ink in the bowls was clear.

Noticing his gaze, Iruka grinned then slid one of the bowls over to Kakashi and took a seat across from him.

"The trick is to infuse the right amount of fire chakra into the ink."

Kakashi pushed up his forehead protector and watched as Iruka made an ox hand seal, then transferred chakra into the ink. For a brief moment, it shimmered in the bowl. But that was it. It didn't change colors, the chakra didn't linger. It was still just clear ink. 

Iruka dipped a brush into it and wrote a few short words on the paper, blowing to dry it. Kakashi focused on the paper itself, not the shape of Iruka's mouth as he blew on it.

"Invisible ink," Kakashi said. The paper had dried to the point where it looked blank again. Even the Sharingan was only detecting a faint outline of what Iruka had written.

Iruka nodded.

"How do you reveal it?"

"The same way you charge it," Iruka said then made the ox sign again before running a thread of fire chakra through the paper.

On the paper, three words shimmered. _Will of Fire._

The moment Iruka stopped pushing chakra through the paper, the shimmering faded, then stopped.

"You can write anything you want over it with regular ink, but the message will still show through once you activate it with chakra. And it should only activate with the chakra it was written with or chakra similar to it. Obviously there are limitations on who you could send a message to in this way, but it works great for anything within the clan."

Kakashi nodded. It seemed simple enough. 

"Here," Iruka said, pushing the paper across the table towards Kakashi, "you try it."

Kakashi made a quick ox hand seal, then tried to gather enough of Iruka's chakra to activate the ink. It was still agitated and excited under his skin. Iruka was close enough Kakashi's entire body buzzed with his presence, making him fight the urge to shift in his seat. It was hard to separate one chakra from the other, and it'd be a lot easier to mold if it weren't quite as active, but he thought he was getting the hang of it. Using a thread of fire chakra, he ran it through the paper.

And immediately had to drop the paper as it burst into flames. It burned up before it hit the table.

He glanced over at Iruka, who was pressing his lips together, trying and failing to conceal a grin. "A little less chakra next time, maybe." 

Iruka used the remaining ink in his small bowl to write another quick message, and while his eyes were off him, Kakashi rolled his shoulders, trying to ease some of the tension that had settled into them. If anything, the excitement in his chakra had just gotten worse after he'd used it.

Iruka pushed the second piece of paper at him and Kakashi waited until his hand was well away from it before he reached out and grabbed it. As excited as his chakra was now, he didn't want to get too close.

This time he used only a fraction of the chakra he had before. The kanji for _shinrai_ lit up on the paper, a red-hot glow instead of a sparkle. When he stopped pushing his chakra through the paper, the glow faded, but the kanji remained charred onto it, no longer a hidden message.

"Hmm," Iruka said, tapping a finger against his lips in thought. And okay, yes, Iruka's chakra was definitely more active now. Kakashi did his best not to squirm in his chair. "Maybe you'd have better luck activating ink you make yourself."

He gestured at the bowl he'd pushed towards Kakashi earlier.

Kakashi used the motion of picking up the bowl to shift again. It didn't help.

"Just a little bit," Iruka said softly, leaning forward, eyes focused on the bowl in Kakashi's hand.

Kakashi closed his eyes for a moment, but that just brought the sensation of Iruka's chakra under his skin that much more into focus. Before he could stop himself, Kakashi rolled his shoulders again. He could do this, it wasn't a problem. He just needed to feed a tiny thread of chakra into the ink, barely even enough to light a candle.

He opened his eyes and focused on the ink. _Just a little bit._

The ink went up in flames.

They both blinked at the now empty bowl in Kakashi's hand.

"Uhh..." Iruka said, "that was... I... didn't even know this ink was flammable?"

"I... don't think it is," Kakashi said, feeling his cheeks burn under his mask.

"Right," Iruka said, giving an awkward chuckle, but the warm, rich sound of it still tickled down Kakashi's spine, spreading out in warm waves through Iruka's chakra. He shifted again, only to have Iruka's focus suddenly snap onto him, suspicion in his eyes.

"You're nearly as antsy as Naruto. Are you always like this when you're inside for too long?"

"Uh," Kakashi said eloquently, "not usually."

Iruka just watched him until Kakashi elaborated. 

"I can't quite get my chakra under control at the moment. Or, well, _your_ chakra," Kakashi said, and he knew he blushing hard enough that even his mask wasn't covering it all. His ears were hot.

Iruka frowned. "Is it always like that?"

"No, it settles down after..." He trailed off, not wanting to explain it further, but Iruka was too smart not to make the connection.

"After we touch?"

Kakashi nodded.

Without hesitation, Iruka held out his hand like it was as simple as that. "So touch me."

And wow, that was not how Kakashi had always imagined him saying those words, but he reached out a hand anyway.

"Are you sure?" he asked before he got too close. "This might be painful."

Iruka just scoffed and reached his hand closer to Kakashi.

It turned out he didn't even need to touch him. The moment their hands got close, a loud snap sounded in the room, the crack of a log splitting in a fire.

Iruka shook out his hand.

"Sorry," Kakashi said, but Iruka just shook his head too. 

"It's fine. It's just a little..."

"Shocking?" Kakashi finished and Iruka snorted.

"I didn't want to say it. Better?" he asked.

Kakashi took a deep breath. "Yeah," he said. His chakra felt more stable again, calmer, not like it was trying to vibrate out of his skin to get to Iruka.

Iruka took his bowl and refilled it with another small portion of ink.

This time, it worked. The ink glittered for a few moments, then went clear again.

Kakashi carefully wrote on the piece of paper Iruka handed him, turning it towards Iruka as he ran a thread of chakra through it. 

The words _Icha Icha_ glittered at Iruka and he snorted again.

"One track mind?"

Kakashi eye-smiled at him, and Iruka just shook his head.

They tried it a few more times to make sure Kakashi had the hang of it, exchanging papers at the end to see if they could activate each other's messages.

Iruka's laughter when he revealed Kakashi's _#1 Teacher Award_ was priceless. 

Kakashi nearly choked when he saw what Iruka had written. 

_"To me, love is life."_

The first five words of _Icha Icha Paradise_. His mouth hanging open, Kakashi stared at Iruka.

Iruka blinked at him innocently. Even ignoring the fact that he was blushing, it was about as convincing as every time Naruto had given him the same look.

"Same time, same place in three days?" Iruka asked after a beat. "This room should still work as long as you aren't too bad a student."

Kakashi could only nod.

~*~*~

The second time, Kakashi did feel Iruka coming, the buzz of his chakra matching his anticipation as Iruka drew nearer.

He was curious to see where Iruka was going with this. Invisible ink was cool and all, but it wasn't much of a battle skill. Kakashi doubted he'd ever use it. But he also didn't think that was the main thing Iruka intended to show him. 

As they got settled into the room, Kakashi resigned himself to the constant distracting rush of his chakra around Iruka. He'd do better controlling it than he had last time.

As if reading his mind, Iruka reached across the table, holding out his hand. Kakashi blinked at it for a moment.

"Best to have stable chakra for this," Iruka said, something a little mischievous in his smile.

The shock wasn't as bad as before, but it was still loud enough to make Kakashi cringe and strong enough to make Iruka shake out his hand again as he used his other to set up his supplies.

After he'd finished, Iruka grabbed a small rectangular piece of paper and held it so Kakashi could see, flipping it over to show there was no visible writing on either side. He made an ox hand seal and tossed the paper up into the air. The ink shimmered for one brief moment, Kakashi's mind needing an extra second to process the pattern he'd just seen.

Then the tag exploded. A tiny, controlled explosion perfect for the small room they were in, but an explosion all the same.

Now _that_ was cool. And useful on the battlefield. Exploding tags were distinctive, their black ink serving as a warning. But if he had tags that looked harmless, well, there were definitely situations that would come in handy.

And that was how they spent their afternoon. First learning the basics of making exploding tags, since Kakashi had never had to make his own before. Then doing it in invisible ink. He could carry a stack of these and they'd look like plain notepaper.

While they worked, Iruka chattered away, naturally keeping up a steady stream of conversation. He talked about how his family had specialized in seals, and how he wasn't as good as his parents, but he'd learned a decent amount from them.

The Uminos had never been a large clan, from what Kakashi knew, but even smaller clans tended to have a few jutsu that were ideal for their chakra. They weren't bloodline limits, just jutsu that worked best for clan members. Each clan had unique chakra that often lent itself to certain types of jutsu. The Naras had their shadow jutsu, the Yamanakas had their mind fuckery. Hatakes had specialized in weaponized lightning. And while Kakashi could copy and use jutsu from other clans, they were never _quite_ as good as an actual clan member could do because the jutsu were designed to work best with the clan's chakra signatures. Umino chakra, apparently, was the kind of stable, steady chakra that lent itself perfectly to making seals and tags.

It was oddly familiar listening to Iruka talk, soothing even. He could get used to this far too easily.

Finally Kakashi had made a few tags that Iruka deemed acceptable.

"And now the fun part," Iruka said, holding up one of the tags. "Shall we have a little bit of a practicum?"

If Kakashi had thought hanging out with Iruka was enjoyable, blowing things up with him was even better.

They went their separate ways after a bit of destruction, and Kakashi couldn't wait to see what else Iruka had up his sleeve.

~*~*~

Kakashi's schedule was significantly more open than Iruka's so they meet whenever Iruka had extra time. It amazed Kakashi how easy it was to work with him, how right it felt. Iruka showed up to each of their sessions with a well-organized plan. Every time it was something new, often building on what they'd done previously.

The third session had been using chakra-infused ink on the tags to work as a kind of remote control trigger. 

"It's not foolproof," Iruka had admitted sheepishly. "It works in a similar way as the Yamanaka mind transfer jutsu. You sent your chakra out to activate the ink, but it has to be in a straight line, on target, and with a clear path. Otherwise nothing is going to happen."

He was playing down its usefulness, and it might have its limitations, but Kakashi could imagine multiple scenarios where it could be utilized in a fight. 

Kakashi wasn't surprised when a fair number of Iruka's jutsu turned out to be ideal for seals and tags, as well as a few that would definitely help promote the idea that teachers had eyes in the back of their heads and ears that could hear exactly what students hoped they wouldn't. He did raise an eyebrow at the ones that seemed mainly suited to pulling pranks and causing chaos. Suddenly a few of the more outlandish rumors about Iruka were making a lot more sense. 

There had been one in particular that had always made Kakashi curious. 

"I heard this rumor about you once," Kakashi said after one of their sessions.

"All lies," Iruka said without missing a beat.

"I don't know, after all the explosives you've shown me..."

"Oh god, not that one."

Kakashi tried not to grin. "So I take it you didn't actually blow up the Academy with a bunch of tags right after you became a genin."

Iruka groaned and buried his face in his hands. "It was a genjutsu explosion. One final prank before I left the place. That rumor has taken on a life of its own."

"Blown up, would you say?"

Iruka snorted and shook his head. 

"But, Sensei, does this mean you have a genjutsu explosion tag?"

"Maybe," Iruka said, grinning at him. "Want that to be our next session?"

Kakashi wanted that very much, but it was just one more thing on a long list of wants.

~*~*~

Showing someone all the secrets of your chakra was deeply personal, but Iruka didn't hesitate, he didn't hold back. He showed Kakashi everything that made his chakra uniquely _Iruka_ , and Kakashi drank it all in.

He was willing to bet that many of the things Iruka was showing him were less _Umino_ jutsu, and more _Iruka_ jutsu, particularly the ones that were well-suited to pranks or teaching, though Iruka said nothing about creating any of them.

"You don't mind me knowing these?" Kakashi asked after Iruka had shown him a few of the more mischievous ones. "There's a saying about magicians and secrets that might be applicable."

"Honestly? I never thought I'd be teaching them to anyone. I didn't think I'd have the chance," Iruka said with a shrug. "I thought I'd be the last one to use them."

Kakashi understood that all too well. He'd long known his family jutsu would all be dying with him.

"I mean," Iruka said, tone light, "I use the invisible ink to write grocery lists and to do lists. It's not like I'm treating it as if it's something sacred."

Kakashi couldn't help but wonder if that wasn't Iruka's way of keeping something of his family alive for as long as he could, the same way Kakashi had used his father's tanto until it'd been broken. Some little piece of the people who came before you when you knew no one would come after.

~*~*~

Other people might have been surprised at how well Iruka's jutsu worked with Kakashi's chakra mixed in, but Kakashi wasn't. The way their chakra worked together felt right, but then again, Iruka had always felt _right_ , even before all of this had started. Now Kakashi had proof of it sparking to life on his fingertips whenever they were near. He had the buzzing feeling of _home_ and _family_ resonating under his skin whenever they were close, and the closer they were physically, the more his chakra reacted.

Tsunade had thought it might subside once Kakashi got used to having Iruka's chakra in his system, but it showed no signs of abating. He didn't want it to, at least not completely, not with how alive it made him feel.

Kakashi's chakra flickered like lightning and burned like fire whenever he was next to Iruka. He had never felt anything like it before. It was familial resonance, but stronger, more powerful, deeper inside himself. At times, it felt almost wild. He'd managed near perfect control of his chakra from an age most children were barely entering the Academy. Losing control, even just a little bit, was a new experience and one he was enjoying immensely.

It was distracting at first, but only until they touched. Just the quickest brush of skin against skin was enough, though Kakashi couldn't help but want more. Each time there was a spark, a jump of chakra, and then things seemed to neutralize. When they were away from each other for an extended period, Kakashi's chakra would get excited as soon as it felt Iruka getting close again. The longer they were apart, the more he noticed it, to the point where his chakra was just this side of uncontrollable. But touching Iruka seemed to ground it, to even out the charge. It turned the agitation into a pleasant, homey buzz.

"Is it uncomfortable?" Iruka asked after a particularly strong shock, shaking out his hand again. He always said the shocks didn't hurt, just surprised him even when he knew they were coming, but they still made Kakashi wince each time they happened. "My chakra, I mean."

Kakashi shook his head. "Before the shocks, it's not uncomfortable, just overly active." He paused, not sure if he wanted to say what he was about to, but he pushed on anyway. "After, it feels a little like familial resonance. Not exactly the same, but similar."

"Oh," Iruka said, eyes widening and cheeks growing pink at the implications. "Sorry."

"No, it's fine. Better than the alternative," Kakashi tried to joke, then became more solemn again. "I just hadn't felt it in a long time."

Iruka nodded. "Same." They'd both lost anyone close enough to feel resonance with a long time ago. 

It might have been an unplanned side effect, but if Kakashi had to feel resonance with anyone, he was glad it was with Iruka.

~*~*~

Iruka used seals as listening devices. He carefully placed them around a room, in hidden corners and under furniture, and tied them to a master seal, which he could set up elsewhere to use as something like a radio. When Kakashi asked if his parents had taught him this particular seal, Iruka had side-stepped the question by explaining something related that his parents had shown him. Kakashi was increasingly coming to realize that meant Iruka had in fact made it, he just didn't want to seem like he was bragging about it by saying yes.

If Kakashi hadn't had a massive crush on Iruka before, finding out how utterly creative he was with his fierce intellect would have sealed the deal, pun fully intended. As it was, a dozen sessions in, Kakashi was absolutely _gone_ on him. Any hope he'd had before of his crush eventually fading away had gone up in smoke the first time they'd used explosive tags with invisible ink to blow something up.

And now here they were, hunched together over more seal paper as Iruka showed him the way he connected the listening tags with the master tag. Kakashi leaned in closer, partially for a better look at a particularly tricky bit of calligraphy and partially just to be _closer_ , when Iruka's brush faltered and he took a sharp breath then let it out with a soft _oh_. 

He turned to look at Kakashi. The close distance between them seemed even closer now that they were looking into each other's eyes. Iruka blinked at him slowly as he took a deep breath, chest raising with the extent of it. Kakashi could only stare.

"I can feel your chakra, or mine, or whatever," Iruka said after a moment, his cheeks were a lovely shade of pink. His eyes slid shut like he was concentrating on something inside himself. "It's really faint, but it's there. Just a low buzz in the background."

With his eyes shut like that, it was so tempting to lean in closer, but Kakashi didn't.

"Sorry," he said instead, remembering what Iruka had said weeks ago, like the resonance was an intrusion that needed to be apologized for.

"Don't be," Iruka said, opening his eyes and looking directly into Kakashi's. "I see what you mean now, it is a little like familial resonance, just somehow more..." he seemed to struggle for a word to describe it correctly.

_Perfect_ , Kakashi thought, but he didn't say it. _Complete, thrilling, intense._

"More of an echo of your own voice?" Kakashi asked instead. It was true, it just wasn't the whole truth. The resonance didn't just feel like he'd found something similar or related, it felt like an inextricable part of himself.

Iruka nodded, smiling at Kakashi in the softest of ways and Kakashi found himself swallowing hard, the hum he had always felt around Iruka since the transplant was now all he could focus on, the sonorous way it moved throughout his body. Again he thought about how easy it would be to lean closer to Iruka. He wondered what their shared chakra would do if he slid his hand under Iruka's shirt and brushed his lips against the line of his jaw.

Iruka jerked, like Kakashi had just shocked him, and seemed to realize they'd been staring at each other for longer than could ever be considered polite.

"Right," he said, an edge of uncomfortable laughter in his voice, "this part here can be a little tricky." His brush wavered for a moment but then was steady on the paper again.

Kakashi tried to focus on the work at hand, but it was hard when all he could do was picture Iruka with his eyes closed, focused on the feeling of his chakra reacting to their proximity. He doubted Iruka would ever feel it as strongly as he did, he would never have as much of Iruka's chakra as Iruka had of his own, but it was fascinating to know he could feel it at all. Kakashi would always feel the stronger pull, a satellite being pulled along by a planet's larger mass. He found he didn't mind the idea of orbiting around Iruka at all.

~*~*~

Training with Iruka was a habit Kakashi was more than willing to form, even if it probably wasn't good for him in the long run.

Each time Kakashi asked Iruka to train with him, it sounded like an invitation to so much more, to the point where he wondered how Iruka could ever mistake it for anything else. But Iruka always smiled and agreed, never seeming to understand what Kakashi was asking underneath his question.

It didn't help that more than a few of Iruka's jutsu felt like dirty secrets for just the two of them. The one that let them communicate like a whisper in each other's ear was a particular kind of torment when they were testing it out. Having Iruka's voice in his ear, low and irresistible, reminded Kakashi too much of his book-reading Iruka fantasies, of other things he'd like to hear Iruka to whisper.

They each headed in opposite directions to test it out, wanting to see how far away from each other they could get while it still worked.

"So what would you like to talk about, Sensei?" Kakashi asked after Iruka was out of sight.

"Hmm," Iruka said, "what have you been doing with all your extra time the last few months?"

That _hmm_ was particularly distracting. It made him think of the times narrator Iruka had made the exact same noise. He willed himself not to shiver, not to let how that sound affected him show in his voice. "Just getting caught up on some reading."

"Do I even want to know what?"

"Maybe. Have you ever read Jiraiya-sama's works?"

Iruka laughed. "You might be surprised."

"So you have read it."

"Not all of it." 

Kakashi's heart caught for a moment. "Any favorite parts?"

There was a pause. Kakashi wondered how hard Iruka was blushing at that moment. He wished he'd thought to have this discussion when he could actually _see_ Iruka, not just hear him. 

"… one or two," Iruka finally admitted.

Kakashi grinned. "The Fight at the Phallic Tower of Overcompensation?" he guessed before he could think better of it. 

Iruka made a choking sound then sputtered, "The Phallic Tower of Overcompensation?"

"Ah, the final fight in _Violence_." Kakashi could kick himself. That was what audiobook Iruka had called it, chuckling as the Princess managed to kickass while still maintaining the bare minimum of dignity in her wardrobe malfunction waiting to happen of a yukata. 

"Ah," Iruka said with a nervous laugh, "that one. That was pretty entertaining."

Something itched at the back of Kakashi's mind. "When did you read them?"

"Oh, not that long ago," Iruka said, and yes, he was _definitely_ sounding suspicious.

"What did you think of the end of _Tactics_?" Kakashi asked, pushing for more.

"Uh," Iruka said, then paused a moment. "I never got that far?"

"That's too bad. There are a few scenes I think you'd _enjoy_." And maybe there was some innuendo in Kakashi's tone at that, but who could blame him?

Iruka made a noncommittal noise.

"You can read mine, if you'd like," Kakashi offered, more than a hint of tease in his voice, and was rewarded with a coughing sound in his ear. He _really_ wished they were having this conversation face to face.

Iruka cleared his throat. "Are you nearing Training Field 27?"

He was trying to change the subject, and Kakashi let him. "Yeah, should be there in another minute."

"Okay, I think that's about as far as this will work, so we'll probably be fading out soon. If so, I'll see you the day after tomorrow at the usual spot?"

"Wouldn't miss it for the world, Iruka-sensei," Kakashi said. 

The jutsu ended up working for a decent way past Field 27 and they kept up a steady stream of small talk the whole time, carefully avoiding the subject of the books.

Just as the connection started to fade and Iruka's voice became quieter, Kakashi said, "This thing had more staying power than the Prince of Stamina." Narrator Iruka's nickname for the male protagonist in _Tactics_.

He could just barely hear the choked, nervous laughter that Iruka let out before the jutsu broke off and there was silence again in his ear.

Kakashi walked home with a wide grin hidden by his mask and an extra bounce to his step. Maybe, just maybe, he wasn't so delusional after all.

~*~*~

The longer they trained together, the more Kakashi learned the tricks of Iruka's chakra and the more he got used to the new combination of chakra in his system. He figured out how Iruka's chakra worked with his own, tweaking his own jutsu, making them better, stronger. He learned how to control the amount of Iruka's chakra that he used so he wouldn't accidentally make his fire jutsu too strong, and so he could manipulate the amount of it that appeared in the Raikiri and his other signature jutsu.

Their sessions continued, though they weren't strictly necessary anymore. Iruka had taught him most of the family jutsu he knew, but they kept meeting. And that more than anything made hope buzz inside of Kakashi the same way his chakra buzzed when he was near Iruka.

A few times Kakashi had even gotten Iruka to spar with him. The rush of it had his chakra as agitated as it ever got, like the constant equalization that happened when they traded blows couldn't quite keep up with the combination of close proximity and strenuous physical activity. But that didn't stop him from suggesting they do it again. Iruka was an interesting opponent. Even knowing all his special jutsu beforehand didn't prepare Kakashi for how creatively Iruka could use them. Anyone who thought he was weak and would be an easy opponent really needed to rethink their evaluation.

Kakashi taught Iruka a few things in exchange, things that seemed to be well-suited to Iruka's chakra, and Iruka was the perfect student.

Slowly the training sessions transitioned into something a little different. Something that required lunch or dinner afterward, or at least a stroll through the village together. It was an arrangement that Kakashi could get behind. They weren't dates per se, but they weren't that far from it either. 

Now he knew Iruka better, knew what he could do, had an entire list of reasons as to why he was interesting, proof after proof of how clever he was, seen him in a far more personal way than ever before. After all that, Kakashi didn't have a massive crush. What he had felt a lot more like love and he was surprised to realize how fine he was with that.

He almost regretted it when Tsunade finally okayed him to restart his usual mission schedule again and their not-dates had to become a lot less frequent. But missions were part of who he was and being back in the field made him feel useful in a way nothing else ever had. 

He'd never had someone to come home to. There had never been anyone in his life that he needed to complete a mission safely for. Iruka wasn't that person, at least not yet. But sometimes he seemed disappointed when Kakashi had to cancel one of their scheduled meetings because of a mission, maybe just a hint of worry in his eyes. And when Kakashi came back, Iruka seemed genuinely happy to see him again. 

There were times when he was almost afraid he'd electrocute Iruka the first time they touched after particularly long missions, but Iruka just grinned at him and held out his hand, waiting for the brief touch of Kakashi's fingers and the shock that always came with it. If Kakashi's fingers lingered just a little from time to time, he didn't think anyone could blame him.

And if he tossed out a few of narrator Iruka's more choice lines just to see real Iruka's reaction to them, he didn't think anyone could blame him for that either. Iruka was rather adorable when he was bright red after all.

~*~*~

Kakashi picked up his now full travel pack. A month long mission was the last thing he wanted to do right now, not when things were getting so promising. But his village needed him, so there was no question about whether or not he would do it.

Just before he headed out the door, he stopped by his bookshelf. It'd been forever since he'd read the end of _Tactics_ , and even if it didn't come with an audiobook like the rest of the series, he'd been wanting to reread it again. There were reasons why it was his favorite.

His eye caught on the tiny scrap of paper still tucked in the book, and it sparked something in the back of his mind, just the barest hint of a hunch. He took the paper out of the book, looking at it and debating. It really had been more of a whim than anything else that had led him to keep it in the book for this long. He flipped it over in his fingers. Both sides were blank, but still, he wondered.

Taking a deep breath, thinking how foolish he was being, he ran a thread of chakra through the paper.

There was nothing on it.

He flipped it over in his hand, wanting to check the other side just to make sure. And that's when he saw it. A tiny sparkle of chakra right at the edge of the paper, just one swooping line cut off from whatever character it had belonged to.

Kakashi let out the breath he hadn't realized he'd been holding and grinned.

He wasn't delusional after all.

He left the village with extra determination to get back as soon as he could. There was a conversation he needed to have once he got home.

~*~*~

Of course, taking regular missions again meant regular run-ins with missing-nin. At least this time the entire forest around him didn't explode, just a large swathe. Kakashi pulled to a stop as a female missing-nin dropped down in front of him.

He recognized her immediately. She'd tried to sidle up to him at an inn a few towns back. She'd been flirtatious at first, moving into his personal space, trying to touch him casually. Just as casually, he dodged her wandering hands. When he'd made it clear that he was in no way interested, she'd shifted to a friendly, air-headed babble that set his internal alarms off even more than her offering him a drink had. There was too much of a calculated edge to it to seem natural, her eyes were too sharp to make him think there was nothing suspicious in the way she asked question after question about his life and hobbies and interests. Most of it seemed like friendly chatter, but she was digging for information, trying to get him to lower his guard.

He'd finished his drink and made his excuses, heading back to his room for the night, but not before he saw a flash of irritation in her eyes. A clone had slept in his bed that night while Kakashi had stood guard, expecting an attack. It hadn't come, though for the last few days, he'd known he was being followed. So he wasn't surprised now that she was finally revealing herself.

"You should be dead," the missing-nin said. It wasn't in a hate-filled voice, instead it was coldly curious, like she'd found something interesting to study. "Why aren't you dead?"

"Eh," Kakashi said with a shrug, using the time to catalog the land around him. "Well, I am often late."

She blinked at him. "Was that... a pun?" 

Kakashi shrugged again. 

She narrowed her eyes at him, clearly not impressed with his sense of humor. "No one has escaped that jutsu."

She had to be talking about the medical jutsu.

"You should be dead and I want to know why you aren't," she repeated. "If there is a flaw in the jutsu, it needs to be fixed. You killed the last ninja I sent to figure out why, so this time I have to do it myself."

Kakashi watched her carefully. She must have been partners with the missing-nin who had originally hit him with the jutsu. He didn't want to think about the medical ninjutsu those two had come up with together. The last missing-nin he'd faced was likely a hired henchmen, he hadn't seemed like the type to spend time creating highly cruel and destructive medical ninjutsu. 

Kakashi sighed. He really didn't want to get into an all out fight right now, not when he was finally on his way home, but it seemed like there was no avoiding it. He couldn't let someone like this go, not if she was creating weaponized medical jutsu. 

She made that decision even easier by launching a volley of senbon. Kakashi did a quick substitution jutsu, moving away from the battle just enough that he could figure out the best way to attack. He was at a disadvantage here. She knew who he was, but all he knew about her was that she could create some nasty jutsu and he didn't want to get caught unaware by another one of them.

They tested each other, feeling for weaknesses, throwing out jutsu to see how they'd respond. Kakashi attached regular explosive tags with a standard delay to kunai and tossed them at her. She avoided them easily, getting out of the way well before they exploded while still sending rains of senbon at steady intervals. 

She seemed to be a short to mid-range fighter, which played to Kakashi's strengths. He happily avoided long-range battles whenever he could.

Kakashi often tested the ninja he fought, checking their reaction times, seeing how they responded to things, trying to figure out the best way to take them down before going in for the kill. But this missing-nin, she was testing him in a different way. It wasn't just battle strategy, she was studying him, trying to see if there were still traces of the jutsu, trying to figure out if anything about him had changed. He had assumed the first missing-nin had known who he was. With as many bingo books as he was in, it would've been foolish to assume anything else. But from the methodical way this missing-nin was testing him, it was clear they had done their research. 

"You targeted me specifically with that jutsu, didn't you?" he asked as he dodged one of her attacks, this time poison gas. 

"You, or anyone else with enough strength. It killed off most our subjects too quickly. We wanted to see how long someone strong could last before it killed them. Unfortunately, you killed my partner before he could get the necessary information." She didn't sound sad about the death of her partner, the lack of data was the real crime in her eyes. 

He drew chakra for a Raikiri and her eyes flickered down to it. "Interesting," she said, "you have someone else's chakra now. It couldn't have been a blood transfusion, the jutsu runs too deep. How did they do it? They would have needed to completely remove your blood cells. A bone marrow transplant?"

Kakashi grunted, looking for an opening. She took it as an affirmative.

"Hmm, we didn't foresee that loophole. Still, that can be fixed. If I tweak the jutsu so it affects other types of cells as well, not just blood cells, it would prevent that cure."

Kakashi wasn't about to give her the chance to _fix_ her jutsu.

Her hands lit up as well. Kakashi recognized the chakra scalpel jutsu often used for surgery, but in her hands it was an offensive technique. It was too dangerous to go in with the Raikiri while she held her chakra like that. Kakashi was fairly certain he was faster and would be able to take her out, but there was too high a probability that she'd be able to deliver a blow to him before he could get away. They could both end up dead.

Instead, he backed off again. She narrowed her eyes, calculations clear on her face. She had to know that something like a bone marrow transplant would reduce his stamina for a significant period of time afterwards, maybe she thought his strength was fading and he needed time to regroup.

Kakashi didn't let her think about it too long. He sent another round of explosive tags attached to kunai at her and again she easily got out of the way before they exploded. 

The blast made a nice clearing in the forest. Kakashi entered it, making his movements slower than before. Moments later, she joined him, her steps quick and eager, like she could taste her impending victory.

She walked towards him, confident and smooth, hands surrounded by the bright blue of healing chakra wielded as a weapon, pausing only briefly to kick at one of his kunai, the blank paper attached to it fluttering briefly in the air as she did.

She scoffed. "Did you run out of tags and think adding in a few blank ones would fool me?"

He didn't bother answering, instead making an ox hand seal twice, followed quickly by rabbit and monkey seals. At the speed he did it, it probably just looked like he'd faltered for a moment and had to restart the three seal sequence for the Raikiri. He gave himself just a fraction of a second to savor how well Iruka's jutsus worked with his own. They both even had a tendency to start with the same hand seal. Perfect for times like this.

She was probably a sensor, but she was too focused on the Raikiri in his hand to pick up on the burst of chakra that was currently flying in a straight line towards somewhere just a little to the left and behind her. She was too busy trying to figure out how his new dual chakra nature worked to see the blank tag start to glitter.

The explosion shook the clearing, causing her to stagger and lose the delicate control needed to maintain her chakra scalpels. The glow around her hands flickered out.

Kakashi was ready for it. Without hesitation, he swooped in, fire-laced Raikiri ready for the finishing blow. He doubted she'd even seen him coming, still recovering from the sudden surprise of the explosion.

He collected her body in a scroll. She might appreciate the fact that she would be the one being studied now. Hopefully Intel would be able to track down her lab and make sure none of what she'd created got released into the world.

He took stock of his condition. He didn't have any life threatening injuries, but he was dangerously low on chakra. He still wasn't quite up to making as many Raikiri as he had been before the jutsu. Getting back to Konoha quickly was doable, it just wouldn't be pleasant.

He burned up what little reserves he had left, but he got home. The fact that Iruka's chakra replenished itself quicker helped him make it the last little bit of the way.

Tsunade cursing him out as he collapsed in her office after handing over the intel was starting to sound a lot like "Welcome home."

~*~*~

He wasn't surprised to wake up in the hospital. Given how chakra depleted he'd been, it'd been all but inevitable even before he'd passed out in Tsunade's office. What he hadn't expected though, was to wake up to the sound of Iruka's voice. He kept his breath even and pretended to still be out, wanting to hear what Iruka was saying.

_She shivered at the touch of his large,_  
_calloused hands against her soft, delicate_  
_flesh. He was so rough, so manly, always_  
_trying to be so strong, but she knew what_  
_he really wanted, what he needed._

Kakashi recognized the words immediately. They were from one of the last chapters from _Tactics_. 

_"It's okay," she whispered as they broke their_  
_kiss. "I know you want him."_

_"I want both of you," he said, torn between his_  
_two loves._

"Wait," Iruka said, "did Jiraiya-sama actually..."

_"Then have both of us," she said._

_As if on cue, their bedroom door opened and_  
_another man walked in. One he knew so well,_  
_yet not nearly well enough._

_"I want to watch him fuck you," she whispered_  
_and it was his turn to shiver._

"Oh my god," Iruka said, "after three whole books of teasing it, he really is going to let them fuck. _Finally._ "

Kakashi chuckled softly, he couldn't help it, that had been his exact same reaction. "I _knew_ it," he said, voice hoarse. "I knew I hadn't imagined you reading to me."

Iruka jumped, flailing in the chair he'd pulled up beside the bed. "You're awake," he said and Kakashi cracked his eye open. Iruka was just as red as he'd imagined he would be. "Tsunade-sama said you'd be out for at least another day."

Kakashi grinned. "Guess I'm not late after all."

Iruka rolled his eyes, but looked happy.

"I left your bookmark in for you," Kakashi said, grinning at him.

If anything, Iruka just got redder.

"How often did you read to me while I was in the coma?"

Iruka looked away. "Well, you see, I was in the room next door the night before the surgery and for a few days after, so it was easy enough just to stop by."

"And before that?"

"Well, they had to run tests and things so I figured while I was around..."

"And then after you were out?"

"Maybe."

"How often did _maybe_ happen?"

Iruka was bright red and he wouldn't meet Kakashi's eyes. "I read somewhere that coma patients do better when they have people visiting them, talking to them and stuff. I tried talking at first, but I just didn't have much to say that I thought you'd be interested in. I mean, would you really want to hear all about the crazy things my students do?" Kakashi didn't interrupt him, but he did want that. He wanted to hear everything Iruka had to tell him. "Gai had brought your books just in case you did wake up, and they were just sitting there, so I thought why not."

"Which still doesn't answer how often _maybe_ happened."

Iruka looked like he was about to die of embarrassment, but he stared Kakashi straight in the eye, a little bit of a challenge behind all his blushing, daring Kakashi to tell him he'd done something stupid. "Every day until you woke up."

Kakashi's heart skipped a beat. If Iruka thought he would make fun of him for something like that, he had another thing coming.

He couldn't help himself, he reached out his arm and brushed his fingers against Iruka's wrists. The tiniest of shocks passed between them. "Thank you."

The touches had always been quick before, but he didn't take his fingers away this time, instead letting them linger on Iruka's skin like he'd always wanted to. 

Kakashi had thought he might be in love with Iruka before, there was no question in his mind now. He wondered if there was a way to get Iruka to read the books to him when he was awake, when he could remember all of it properly and watch Iruka as he did it. Maybe both of them curled up in bed together, but he pushed the idea to the back of his mind for the time being. It didn't seem like the type of thing you did before you had your first official date. Surely he should wait to ask until after their third date at least.

He slid his fingers loosely around Iruka's wrist, trying to tug him closer. Iruka didn't let him, but he didn't pull away either.

"Are you doing this because of the chakra? Because of the way the resonance makes you feel?"

"No. I'm doing this because I've liked you since before all of this happened and the more I get to know you, the more I like you. And because you were willing to sit by my hospital bed every day for over a week just to read me porn. And because there's no one else I'd rather be with, no one better than you. The resonance is just a bonus."

He tugged again on Iruka's wrist and this time Iruka let himself be pulled into a short, chaste kiss. They'd have to save the rest until Kakashi could move more than just an arm, but for now, this would do. 

Even through the material of his mask, even with his chakra still depleted, Kakashi could feel an extra little hum as they kissed. He wouldn't mind if the effect never faded, but if it ever did, he knew Iruka would still feel like home.

~*~*~

**Notes for the Chapter:**

> The main inspiration for this came from [this Narutopedia article](https://naruto.fandom.com/wiki/Chakra) \- "One's chakra signature can be altered by absorbing DNA from multiple people." and "In the anime, chakra signatures that are similar to each other (such as that of a parent and child, or tailed beasts) are suggested to resonate when near each other." And in the 4th Shippuuden movie, Minato says similar chakra resonate when they are close and that enhances their strength. I thought the idea of chakra resonance was interesting but it wasn't really developed, so this happened.
> 
> I debated a lot about how I wanted to do this. The options were between this, a kidney transplant, or a blood transfusion. The blood transfusion was particularly interesting because the effects would have been temporary. I played around with the idea that ninjas who don't take combat missions very often donate blood frequently and medic-nin try to use blood from only one person at a time to limit the potential side effects of DNA/chakra mixing. (And some of that did still work its way into the fic.) 
> 
> In the end, I settled on this because I liked the idea of the resonance building slowly over time as they got to know each other more than I liked the idea of it starting out strong and then fading away, though that would have been an interesting contrast; the resonance fading as they grew closer. I was however amused by the idea of Kakashi liking the feeling of his chakra reacting to Iruka and making a bad joke about how it made getting his ass kicked worth it because his chakra reacted to Iruka more after each transfusion and Iruka being like DON'T EVEN JOKE ABOUT IT, OR ~I'LL~ KICK YOUR ASS. IN A WAY THAT WON'T REQUIRE BLOOD. But you can't write them all.
> 
> Also, a variation of this prompt from the 2nd kink meme got folded into the fic: "People in comas do better when they have someone visiting them: reading to them, playing music, rubbing their hands. Iruka visits Kakashi in the hospital after his battle with Itachi. He sees Kakashi has practically 0 visitors save for Sakura who drops by flowers before going to stay with Sasuke. Every night after classes or mission desk duty, Iruka stops by and stays with Kakashi until visiting hours are over." Along with the idea that some patients seem to remember what was said to/around them while they were in their coma.
> 
> Super long notes, oops. Anyway, thank you for reading! I hope you liked it! Next chapter is just 1.5k. Two scenes from Iruka's POV. It should be posted early next week.


	3. Bonus Scenes: Iruka's POV

The first time Iruka saw Kakashi in the hospital, his room was a medical nightmare. He was connected to half a dozen machines that constantly transfused him with new blood to keep the jutsu at bay. Even with the continuous removal of the infected cells, small tremors still wracked his body.

"You didn't need to show me this," he told Tsunade. "I would have donated anyway."

She just shrugged and failed at looking innocent. "We have some things we need to prepare before we can do the donation. Your surgery will be in three days."

Iruka came back the following day without her. He sat by Kakashi's side, watching the shivers that ran through his body, listening to the sounds of the machines around them. He'd heard coma patients could occasionally remember what had happened in the room while they were out, that some reported hearing what had been said to them, that talking to them might actually help. Some medic-nin believed that those with loved ones around them recovered better than those without visitors, so he tried to talk.

As a teacher, he should have been used to having one-sided conversations with someone who might not be listening, but it still felt awkward. It was an odd feeling, talking about his day to Kakashi. He imagined it had to be boring, listening to the things his students got up to and lessons Iruka was trying to teach them. Teacher gossip didn't seem like Kakashi's thing, neither did gripes about mission room work. _Kakashi_ was one of those gripes more often than not after all. He found himself lapsing into silence, trying desperately to find something more interesting to talk about. 

Someone might get the wrong idea if they saw him sitting here. Like Iruka was Kakashi's significant other, waiting for him to wake up, which wasn't a likely scenario. At least not on Kakashi's end.

Iruka had gotten to know Kakashi a little better over the years since he'd been assigned as Naruto's team leader. If Iruka had developed a little bit of a crush on him, he didn't think anyone would blame him. Many people had crushes on Kakashi, though Iruka thought they were often for the wrong reasons. People liked him because he was strong, his image was cool. They clearly didn't know Kakashi all that well. 

Iruka liked him for other reasons. For his strong desire to protect the village, for the way Naruto respected him, for his dozens of personality quirks that spoke of hundreds more hidden beneath. Cool was the last word Iruka would use to describe Kakashi. Capable of doing cool things, maybe, but definitely not cool himself. And Iruka liked that about him, liked that underneath his aloof image, there was so much more to him. If anything, he just seemed like a big dork. It was ridiculous how much that gap appealed to Iruka.

But it wasn't something he'd admit. Nothing would come of it. It was just a little crush that would fade away eventually. It also wasn't the reason he was doing this. Not the donation at least. He would have done that for any leaf-nin in need. And from Kakashi's current state, it was easy to see that need.

Sitting next to him while he was in a coma though, that was likely the crush's doing, Iruka could admit that much.

Finding topics of conversation didn't get any easier the longer he sat there. He cast his eyes around the room, hoping for inspiration. There wasn't much to go off of. His eyes landed on the pile of books on Kakashi's bedside table. It had been nice of Gai to bring them, but they were pointless. Kakashi wouldn't be reading them anytime soon. 

Still, there was nothing else in the room and at least Iruka knew that was a topic Kakashi would like.

"I've never read those," he admitted, "but I've always been a little curious. Don't tell anyone I said that. But the two bookshops in town that carry them are run by families of former students. And the head librarian is the cousin of our current principal. It just never seemed like a good idea to buy or borrow any of them. I couldn't imagine what parents would think if that got around the village. Anytime I try to picture it, I end up with these horrendous visions of mobs of parents storming the school, demanding my resignation." He laughed a little. "You definitely need to be a jounin to read things like that publicly."

It wasn't until the next day, after he'd once again run out of mundane topics to discuss, that Iruka picked up one of the books.

He was immensely glad Kakashi was in a coma when he reached for _Icha Icha Paradise_. He could feel his cheeks burning and didn't need someone there, watching him, adding to that embarrassment.

Glancing around nervously, almost expecting a nurse to come in at any moment, or worse, Tsunade, he opened the book to the first page.

_"To me, love is life. Love is everything, you see."_

Iruka held back a snort. As far as first lines went, that was far from the best he'd ever read, but he continued.

It... didn't get much better. Iruka had always thought books were pure smut, page after page of sex. And while they did have their fair share of that, more than their fair share, really, they also had a healthy dose of every ridiculous romance trope he could think of. They were tawdry and absurd, and if Iruka was being honest with himself, more than a little entertaining. 

It took him a while to get over his embarrassment at reading them out loud, especially the sex scenes, but he found it harder and harder to put them down, even as he found it harder and harder not to make asides and jokes about the _rising action_ , so to speak. 

He'd never admit that he was enjoying himself to anyone but a comatose Kakashi. The books took him through their surgeries, through his recovery, and he'd almost finished by the time Kakashi woke. 

Iruka wasn't disappointed that Kakashi was awake, he was relieved, but if Kakashi had waited just one more day, two max, he would have been able to finish the series. He didn't fail to realize how bizarre it was that he wanted to know how the books ended. That was something he never would have thought possible, even if he had been curious about the series. 

He wasn't sure if he'd ever have an opportunity to read the rest, maybe he could pick up a copy of _Tactics_ the next time he was on a mission that took him out of the village, but if he did get the chance, he'd take it.

~*~*~

In retrospect, after Iruka had found out that Kakashi actually _remembered_ him reading the books to him while he was comatose, he really should have expected this.

They were in Kakashi's apartment after their third date. Nothing had happened yet, but it was heading that way, and Iruka was looking forward to it. 

Except Kakashi was eyeing his bookshelf more than Iruka at the moment. He looked at his books, then looked at Iruka, then eyed his books again. Iruka was very worried about where this was going.

"I have a favor to ask," Kakashi started to say, clearly trying to sound casual. "You spent hours reading _Icha Icha_ to me..."

"Oh god," Iruka said. He could already feel himself blushing.

"Could you maybe-"

"Please don't."

"Read the rest to me?"

Iruka covered his face with his hands. This wasn't happening.

"While I'm awake."

"Why?" Iruka asked, peeking at Kakashi between his fingers.

"It's just that I have the rest recorded, but now whenever I get to the last few chapters of _Tactics_ , they don't have an audio commentary from you, and I really want one." Kakashi was giving him big puppy dog eyes, only mildly lessened by the fact that just one was visible. 

"We could use your whisper-in-the-ear jutsu. Or I could pretend to be in a coma if that helps," Kakashi said.

Iruka wasn't sure _anything_ would help. But that didn't stop him from saying that he might. Someday. Eventually. They could work up to it. And if the look Kakashi gave him was any indication, Iruka wouldn't regret it in the slightest.

When Iruka did get around to reading the rest of _Tactics_ to Kakashi, it was pretty slow going. Kakashi tried to be on his best behavior, but he had a hard time keeping his hands to himself. And when he got Iruka to reread a select few scenes from all the books, it was even slower going. Not that either of them minded.

~*~*~

**Notes for the Chapter:**

> I have to say, I'm really happy this is finally finished. I started writing it literally years ago. ^__^;;
> 
> The "To me, love is life. Love is everything, you see." line is from ep 494 of the anime when Kakashi has Iruka read the scroll his student stole and it turns out to be Icha Icha Paradise.
> 
> Thank you for reading! I hope you liked it! Comments and kudos are always appreciated! ♥


End file.
